Editorial - Lohmann Information

Publisher:LOHMANN ANIMAL HEALTH GmbH & Co. KG; LOHMANN TIERZUCHT GmbH

www.LAH.de · www.LTZ.deCuxhaven, Germany

Editor: Prof. Dr. Dietmar Flock · Akazienweg 5 · D-27478 Cuxhaven · [email protected]

Cuxhaven, April 2007

Editorial

Ladies and gentlemen, friends and colleagues:

Since we started publishing Lohmann Information in its new online format, the number of subscriptionshas steadily grown. This issue will be mailed to more than 2100 addresses in 107 countries. We trustthe topics chosen as "food for thought" will find your interest and appreciate your comments. You arealso welcome to send us addresses of colleagues who like to receive future issues of our publication.

1. In his review of the book "Protein - Population - Politics", Prof. Gerhard Flachowsky, FAL,Braunschweig, focuses on sustainable protein supply for the growing world population from thenutritionist's point of view. The questions raised are indeed complex and solutions must be foundin a global context. The basic needs of people with different purchasing power have to be met, butanimal ecology and environmental concerns will play an increasing role in the search for sustain-able solutions.

2. Satisfying basic nutritional needs is not only a question of quantity, but also involves food quality andsafety, especially freedom from food-borne agents. In his article "Preventing Salmonella infectionsby rationally designed feed additives - the use of organic acids", Dr. Filip Van Immerseel,specialist in Salmonella control in poultry at Ghent University, reviews the use of organic acids inpoultry feed and advocates a new approach, aiming at an increase in the butyrate producing florain the chicken caeca.

3. The improvement of food safety by controlling zoonoses is a major issue in the EU while imple-menting "Regulation No. 2160/2003 of the European Parliament on the control of salmonella andother specified food-borne zoonotic agents" until 2013. In his article "Control of Salmonella andother zoonotic agents in the European Community", Dr. Matthias Voss, head of the VeterinaryLaboratory of LTZ in Cuxhaven, reviews the current legislation and time frame for the control ofsalmonella in poultry and pig production.

4. Production of safe food of animal origin starts with healthy animals. Hatcheries and associatedparent farms play a key role in this respect, as emphasized in "Breeder farms and hatchery asintegrated operation" by Prof. Hafez Mohamed Hafez, Berlin, an internationally recognizedauthority on poultry health and currently President of the World's Poultry Veterinary Association.

5. Beyond the challenge to produce poultry meat and eggs at low cost, in high quality and with minimaluse of natural resources, producers also have to respect and respond to demands of ethicists to treatanimals well. People in the industry may question whether correct beak treatment is an unneces-sary "mutilation", but management practices must be optimized based on current knowledge ofthe bird's physiology and practical experience with less invasive methods. In her paper "Mutilationsin poultry in European production systems", Thea Fix - van Niekerk, Wageningen, memberof WPSA Working Group Welfare and Management takes a balanced look at the general subjectfrom a welfare and industry point of view.

With kind regards, Prof. Dr. Dietmar Flock

Protein – Population – Politics: How protein can be supplied sustainably in the 21st century

G. FlachowskyInstitute of Animal Nutrition of the Federal Research Center (FAL)

Braunschweig, Germany

Introduction

The satisfaction of hunger and thirst are basic human needs noted in the United Nations Declarationof Human Rights. At the time the declaration was written in 1948, the world population was about 2billion people. Now there are more than six billion inhabitants, and in the foreseeable future it couldeasily rise to ten billion.

Hunger is much more than not feeling full. Hunger can also mean a deficit of protein and amino acidsas well as other micronutrients, such as macroelements, trace elements and vitamins. These nutritionaldeficits may cause illnesses and diseases, preventing affected people and populations from performingat their best and adding to the medical bill. Hunger and undernourishment can be seen as thefundamental causes of a spiral of underdevelopment – not tapping physical and mental potential –dissatisfaction and development of local and international tension.

According to United Nations statistics, the WHO and FAO estimate that out of the current 6.5 billionpeople living on Earth, approximately 0.8 billion are not getting enough calories. Many more sufferfrom a lack of certain micronutrients, such as vitamin A, iodine and iron. Reducing by half the numberof starving (and impoverished) people by 2015 is a primary goal formulated by the Food and AgricultureOrganization. At the current rate of increase, the world population will grow to about 8.5 billion withinthe next 25 years (UN 2003).

In this context, the production of high-quality animal-based food takes on a special meaning, along withmore efficient plant production, based on progress in plant breeding, cultivation, pest control, harvest,food preservation and storage.

There is no question that animal-based foods are not absolutely necessary for a carefully balanceddiet. Predominantly vegetarian diets could already feed more than ten billion people. But it is easierto eat a balanced diet when animal protein is on the menu. This is due to the fact that in addition tohigh-quality protein and amino acids, milk, meat, fish and eggs contain essential macroelements andtrace elements as well as vitamins. It is estimated that about 20 grams of edible animal-based proteindaily would be sufficient for a complete human diet (Waterlow, 2001; Young, 2001). According to FAOestimates, livestock food products globally contributed 17% of energy and 33% of protein to dietaryintakes in 2003, and it is predicted that the global average diet will reach the OECD average of 30%of energy and 50% of protein intake (Steinfeld et al., 2006).

At present, an estimated average of 30 grams per day is available per person on Earth, varying fromsix to 80 grams between countries and even more on an individual basis within countries. The differ-ences in protein consumption are due to many factors, including purchasing power and social standing,but also preferences due to ethnic and religious tradition. In addition to physiological dietary aspects,foods from animal sources have a considerable enjoyment value. Rising incomes in developing coun-tries lead to elevated demand and consumption of meat, fish, milk and eggs (Keyzer et al., 2005). Sufficient feed is the most important prerequisite for efficient animal production. Food producinganimals consume about seven times more dry matter than humans all over the world (Table 1).

Protein – Population – Politics: Vol. 42 (1), April 2007, Page 2

Table 1: Estimated dry matter (DM) consumption by humans and farm animals

Production of edible protein of animal origin

The sizeable conversion losses in food production from animal sources are a main point of criticism.On the one hand, these losses contribute to considerable resource consumption (e.g., 3 - 5 kg grainto produce one kg pork), on the other hand to the excretion of nutrients that pollute the environment(Flachowsky and Lebzien, 2006; Verstegen and Tamminga, 2006).

As shown in Table 2, protein production via milk and eggs is more efficient and more environmentallyfriendly than via pork and beef. As the feed conversion into food improves, the excretion decreaseswith higher animal performance.

Lower plant yields and lower animal performance require more land to produce a certain amount ofprotein of animal origin. The land area needed per inhabitant and year is calculated in Table 3 underconsideration of plant and animal performances, the ratio of protein from meat and milk, and the levelof consumption of protein of animal origin.

In addition to the traditional competition of land use between production of vegetarian food for humanconsumption and feed production for animal production, land area is increasingly being used forbioenergy/fuel production in response to the challenge of global warming (Keyzer et al., 2005). Possiblestrategies to overcome this situation include:

- Continued investments to increase plant yield and animal performance by traditional and innova-tive biotechnology.

- Improved efficiency of utilizing limited resources (land, water, fertilizer etc.).

- Lower consumption of animal protein by people with current overconsumption

About two thirds of the world’s ruminants are kept in tropical and subtropical regions, but these animalsaccount for only about one third of the ruminant protein intended for human consumption. The lion’sshare of the world’s meat supply is produced by a much smaller number of animals in the world’stemperate zones. Improvements in efficiency including optimal feeding of animals (e.g. to meet theirrequirements in energy and protein/amino acids) must be recognized as a top priority for farmers andresearchers.


SpeciesNumber (billions)FAO Stat 2005

Consumption (DM)

(kg/day) (billion t/year)

Humans 6.3 0.45 1.0

Cattle, buffaloes, horses, camels 1.6 10 5.8

Sheep, goats 1.8 1 0.6

Pigs 0.95 1 0.35

Poultry 17.4 0.7 0.45

Total (animals) 7.2

Food security and food safety

Global food security means far more than providing enough food. The quality and safety of theseproducts are equally important. Getting enough to eat in the immediate future is of primary concernfor the starving, but even for these people at lowest end of the distribution food loaded with harmfulsubstances cannot be an option, not to mention the fact that food-deficit countries would be excludedfrom international trade unless they meet the food quality and food safety standard of importingcountries.


Table 2: Production of edible protein of animal origin and corresponding N excretion fromdifferent animal species with various performance at recommended N supply(Flachowsky, 2002)

Protein source Production Ediblefraction

Proteincontent

Estima-ted food

Edible protein N-excretion

(averagebody weight)

per day % in theedible

fraction(g per kg

freshsubstance)

competi-tion to

humans(% of

feed)3)

g per dayPercent-

ages

g per kgbody

weight

edibleprotein

kg per kg

of intake

MilkCow 10 kg 95 34 0 323 0.5 0.65 75

(650 kg bw) 20 kg (20) 646 0.9 0.44 70

40 kg (40) 1292 2.0 0.24 65

Goat 2 kg 95 36 0 68 1.1 0.40 70

(60 kg bw) 5 kg (30) 170 2.8 0.23 60

Beef 500 g bwg1) 50 190 0 48 0.12 2.5 90

(400 kg bw) 1000 g bwg (20) 95 0.24 1.6 84

1500 g bwg (40) 143 0.36 1.2 80

Lamb 200 g bwg 50 200 0 20 0.5 1.5 85

(40 kg bw) 400 g bwg (30) 40 1.0 1.0 80

Pork 500 g bwg 60 150 (30) 45 0.55 0.8 85

(80 kg bw) 700 g bwg (50) 63 0.8 0.7 80

900 g bwg (60) 81 1.0 0.6 75

Poultry meat (1.5 kg bw)

40 g bwg 60 200 (40) 4.8 3.2 0.4 70

60 g bwg (70) 7.2 4.8 0.3 60

Eggs 50 % lp2) 95 120 (35) 3.6 2.0 0.6 80

(1.8 kg bw) 70 % lp (50) 5.1 2.8 0.35 65

90 % lp (65) 6.6 3.7 0.2 55

1) Body weight gain 2) Laying performance 3) Depends on amount of roughage and by-products in the diets

Figure 1:

Food security and food safety as ele-ments of health and well being

Various consequences for politicians, agri-cultural producers and also scientists areillustrated in Figure 2. They include fairdistribution of available food, increasedfood production in deficit regions (»helpingthem to help themselves«), application ofcurrent scientific knowledge and invest-ment in research to secure food for agrowing world population. Increasingdemand for high quality animal-basedprotein should be taken into account as areality.


Table 3: Influence of the yield level of plants, the performance level of animals, the ratio ofprotein from meat and milk, and the level of consumption of protein of animal originon land area needs (m² per capita)

Key elements of health and well being

Food Security Food Safety

Two sides of one medal

• State of being secure in the ability to meet one’s nutritional needs

• Freedom from hunger and malnutrition

• Freedom or minimal content of contaminants coming from natural or anthropogenic origin

Consumer

Policy

AgriculturalResearch

I‘m hungry!Is there

anything to eat?

I‘d like somethingto eat!

What do we have?

I‘m nervous!How safe

is my food?

Securing the food supply,Manufacturing enough food

„Food Security“

Food quality,Reducing Surpluses

Food safety,Risk assessment,

Risk communication

„Food Safety“

Increase in agriculturalproduction,

Use of all resources

Quality research,Product quality

Research on safety

Process quality (incl. animal, naturaland environmental protection)

199019801970196019501945 2000199019801970196019501945 2000

Question/Task

Efficient (conservational) use of resources

Figure 2:

Main questions rela-ted to food as well astasks for policy andagricultural research(Flachowsky, 2003)

Consumption(g protein/day)

10 20 40 60

Yield level A1) B2) A B A B A B

Ratio between proteinfrom meat3) and milk (% of protein)

70 : 30 260 105 520 210 1050 420 1560 630

50 : 50 225 95 450 190 900 380 1350 570

30 : 70 190 85 380 170 760 340 1140 510

1) Yield level A per hectare: 4 t DM of cereals, 10 t DM of forage; performance level A per day: 15 kg milk; live weight gain: beef cattle:600 g; pigs: 400 g; poultry: 30 g

2) Yield level B per hectare: 8 t DM of cereals, 15 t DM of forage; performance level B per day: live weight gain: beef cattle: 1200 g;pigs: 800 g; poultry: 60 g

3) Ratio between protein from beef, pork and poultry (in %): . 15 : 60 : 25

The quantitative issue of food security and the qualitative issue of food safety are key elements ofhuman health and well being, as shown in Figure 1 (from Flachowsky and Dänicke, 2005).

Protein – Population – Politics

The goals mentioned above can only be achieved through the efficient use of available resourcessuch as water, fossil fuels, soil and raw materials such as phosphorus, a minimization of pollution infood production and effective conversion of available feed into animal-based food including new lear-ning’s in animal sciences (e.g., optimal feeding incl. feed additives). The many agricultural researchdisciplines, beginning with plant cultivation and including everything from genetic modification toagricultural economics, can and must make substantial contributions to ensure long-term, sustainablefood security.

These and more were the topics of a large symposium held in Berlin entitled “Protein, Population,Politics”. Scientists, farmers and politicians involved in aspects of global nutrition presented interestingpapers on these themes.

Two well-known journalists, Dirk Maxeiner and Michael Miersch, moderated the Symposium, structuredand illustrated the contributions und helped to put the scientific information into understandablelanguage also for people outside the scientific community. The book, originally published in German,was recently translated into English to make it accessible for more readers (Wennemer et al., 2006).Main aspects of the 10 chapters are:

The 1st chapter deals with diet and evolution. The struggle for meat seems to be a driving force inthe evolution of humankind. It required everyone to be cooperative within a group and ready to fightthose on the outside.

Nearly all cultures favor animal protein over other foodstuffs and pursue meat at a cultural expense.A biological mechanism seems to be behind it all. Also today, meat is the determining part of themeal. For example, when choosing from a menu, most people will name the meat portion of the meal.

The 2nd chapter is entitled “The race between the stork and the plow” and deals with the question:How many people can the earth feed? Interesting figures characterize future developments concerningworld population, food need and area per capita available in future. In 2050 only around 1750 m² ofarable land will be available for every person. Much attention has been spent in this chapter to NormanBorlang and his success story with the green revolution (see also Hesser, 2006). Jaques Diouf, theGeneral Secretary of the FAO stated in an interview about the second “green revolution”: “There isn’tany more land. We are exploiting the available production factors to a great extent. The environmentis becoming more polluted. Increased production has to come from high-yielding farming”. Newtechnologies, including biotechnology cannot solve the problems of developing countries alone, butthey can lay the essential groundwork for development.

The 3rd chapter deals with shepherds and rulers or how breeding animals changed the world. Theanimal species and their potential to improve the yields or to use feeds more efficiently are analyzedin this chapter. “Perestroika in the chicken coop” is the title of the 4th chapter. The human attitudetowards animals is changing. More and more countries are experiencing an explosion in the publicdebate concerning animal welfare and animal husbandry.

The 5th chapter, written by Wolfgang Haber, deals with sustainable agriculture: “Accountable to peopleand the environment”. Around 350 000 human generations got their food from hunting and gathering,taking a percentage of biomass that was produced naturally, without being manipulated by humans.But the basic diet became inadequate because of increased population and the humans recognizedthat they could use certain plant and animal species to their own ends by gardens and fields. Naturalprocesses and systems could be transformed to increase the production of that part of the biomassthat was desired as food. In Central Europe, only around 325 generations of farmers were neededto make this fundamental transformation. Humans and their needs are still increasing, which meansthey need increasing amounts of space and food. Ways for more efficient and sustainable production


of protein of animal origin are discussed. Supplementation of diets of non-ruminants with essentialamino acids like lysine and/or methionine may substantially contribute to a more efficient conversionof feed into food of animal origin.

Chapter 6 deals with soybeans on the high seas. Feed, meat and even live animals have becomeinternational commodities. Pros and cons of shipping meat or feed are discussed. Chapter 7 is entitled“Competition vs. cooperation”. Does feeding the world’s livestock take food away from the poor? Thisis a difficult question, and various opinions are offered as tentative answers (e.g. Rifkin, 1992; FAO,2002; Keyzer et al., 2005). Animal species, their level of production and amounts of roughage andby-products included in animal feed (see Table 2) influence the competition with humans.

Chapters 8 (“From fisherman to farmers of the sea”) and 9 (“Meatless alternatives”) are relativelyshort (6 and 3 p.) and deal with domesticating fish through aquaculture and alternatives in addition towidely used protein plants like soybeans. Exotic alternatives such as fungi, algae and insects addvariety to the human protein palette. Fish farming will play an important role in satisfying the increasingprotein demand. In 2020 more than 40 % of all fish on the market will be farmed (Delgado, 2000).Around 80% of the world’s fish will be produced and consumed by developing nations. Today’sfishermen will be tomorrow’s farmers on the sea.

The last chapter (10) deals with the “Brave new swine”. The desire for food of animal origin willcontinue to increase sharply in the coming decades. Much needs to be done to ensure a sustainableprotein supply. More activities to improve plant yields and animal efficiency as well as to utilize localresources and by-products are necessary to produce safe food of animal origin (see Figure 1) with lowdemand of land (see Table 3) and low excretion of nitrogen (see Table 2), phosphorus, methane andother pollutions (see also v. Weizsäcker et al., 1997).

Finally an afterword on genuine dialogue is presented by the theologian Roger J. Bush. The authorlooks at modern livestock feeding and sustainable development from an ethical perspective. Themain question is: how can the society find common ground on economic, ecological and social issues?The following ethically relevant areas and questions concerning animal feeds must be consideredand answered by people working with animals:

- Animal ecology: Does behavioral research take into account describable, fundamental needs ofthe animals to be fed?

- Environmental ecology: What effects do feed systems have on the environment?

- The relationship between local and national, European and global “solutions” for using proteinresources.

- Consideration of the rights of people to participate and to fulfill their potential in economically disad-vantaged areas on Earth.

Altogether the authors of the book tried to find answers to the questions “Can the Earth feed everyonein the long term?”; or “Are we making efficient use of the Earth’s natural resources?”; or “What role doanimals play in all of this and how should they be treated?”

It is extremely difficult to find clear answers to such complex and difficult questions, but at least the bookshows how feed production and feeding of animals can contribute to a more efficient production ofprotein of animal origin. Hopefully the book will not only be enjoyed by many readers, but also contributeto current public debate and give impulses to overcome deficits in worldwide human nutrition.

Some of the basic issues raised in this book are also discussed in a recent FAO publication, mainlyfrom an environmental angle (Steinfeld et al., 2006). Clearly, environmental concerns will play anincreasing role in animal production. Political decisions to use more land for bio-energy productioncontribute to the pressure to maximize the efficiency of feed conversion in animal production. Syntheticamino acids will play an important role in any plan to improve global human nutrition while minimizingthe environmental impact of animal agriculture.


Summary

The production of edible protein of animal origin is the primary objective of livestock husbandry. Theprotein intake of people in developed countries is high (more than 50 g per capita daily from animalorigin) and rising incomes in developing countries lead to elevated demand and consumption of meat,fish, milk and eggs.

On this basis, the following questions must be answered: “Can the Earth feed everyone in the longterm?”, “Are we making efficient use of the Earth’s natural resources?”, “What role do animals play inall of this and how should they be treated?” Some answers are given in this paper.

In the first part, fundamentals are presented such as protein production of various animal species(depending on their performance), need for arable land per capita (depending on plant and animalyields), animal protein consumption per capita and the connection with food security and food safety.

In the second part, the book “Protein – Population – Politics” is reviewed in some detail. This book(10 chapters, 160 pages) was primarily written for people outside the scientific community and showsthe responsibility of politicians, scientists and farmers for future developments to satisfy the physio-logical needs and wishes of humans under consideration of physiological, ecological, economicaland ethical aspects. In some cases more questions are arisen than answers could be given. Futurechallenges for all those involved in animal production are shown.

Zusammenfassung

Protein – Population – Poltik: Wege zur nachhaltigen Eiweißversorgung im 21. Jahrhundert

Die Erzeugung von essbarem Eiweiß tierischer Herkunft ist eine der wichtigsten Aufgaben derNutztierhaltung. Der Proteinverzehr der Menschen in den sog. entwickelten Ländern ist bereits hoch(> 50 g je Einwohner und Tag als Protein tierischer Herkunft). Mit zunehmendem Einkommen steigtaber auch in den Entwicklungsländern der Verzehr von Fleisch, Fisch, Milch und Eiern weiter an.

Auf der Grundlage dieser Entwicklung sind u.a. folgende Fragen zu beantworten: „Kann die Erdelangfristig alle Menschen ernähren?“, „Werden auf der Erde die natürlichen Ressourcen effizientgenutzt?“ oder „Welche Rolle spielen Nutztiere in diesem Zusammenhang und wie sind sie zukünftigzu betrachten?“.

Einige Antworten zu diesen komplizierten Fragen werden im Beitrag gegeben. Grundlagen sind imersten Teil beschrieben, wie z.B. die Proteinerzeugung mit verschiedenen Tierarten und in Abhängigkeitvon der Leistungshöhe; der Bedarf der Einwohner an Ackerfläche in Abhängigkeit von Pflanzenertragund tierischer Leistung sowie dem Verzehr je Einwohner an tierischem Protein oder der engeZusammenhang zwischen ausreichender Lebensmittelbereitstellung, deren Qualität und Sicherheit.

Der zweite Teil des Beitrages beschäftigt sich mit dem Inhalt des Buches „Protein – Population –Politik“ und beschreibt einige Aussagen der 10 Kapitel des Buches. Das Buch ist primär geschriebenfür die allgemeine Öffentlichkeit, um Verständnis für die globale Herausforderung der „Welternährung“zu wecken. Es zeigt die Verantwortung der Politiker, Wissenschaftler, Landwirte und all jener, die sichmit Ernährung für die zukünftige Befriedigung des ernährungsphysiologischen Bedarfs und derWünsche der Menschen an Lebensmittel unter Berücksichtigung physiologischer, ökologischer,ökonomischer und ethischer Aspekte beschäftigen. Manchmal entstanden aus einer Frage mehrneue Fragen als Antworten gegeben werden konnten. Herausforderungen für alle Beteiligten werdenaufgezeigt.


References Delgado, C.L. (2000): Outlook for fish to 2020, Washington, www.ifpri.org

FAOSTAT (2002): Food balance sheets. Statistical Databases. http://www.fao.org

Flachowsky, G. (2002): Efficiency of energy and nutrient use in the production of edible protein of animal origin. J. Appl.Anim. Res.22: 1-24.

Flachowsky, G. (2003): Contributions of agriculture to improved food security and food safety. Fresenius Environm. Bull.12: 467-489.

Flachowsky, G. and S. Dänicke (2005): From feed to safe food – Contributions of animal nutrition to the safety of food. In:New Developments in Food Policy Control and Research, Ed: A.P. Riley, Vona Sci. Publ. Inc.: 65-95.

Flachowsky, G. and P. Lebzien (2006): Possibilities for reduction of Nitrogen (N) excretion from ruminants and the needfor further research – a review. Landbauforschung Völkenrode 56: 19-30.

Hesser, L. (2006): The man who fed the world. Durban House Publ. Comp., Dallas, Texas, 263 p.

Keyzer, M.A., M.D. Merbis, L.F.P.W. Pavel and C.F.A. van Wesenbeeck (2005): Diets shifts towards meat and the effect oncereal use: Can we feed the animals in 2030? Ecological Economics 55, 187-202.

Rifkin, J. (1992): Beyond beef: The rise and fall of the cattle culture. Dutton, New York, 280 p.

Steinfeld, H., P. Gerber, T. Wassenaar, V. Castel, M. Rosales and C. de Haan (2006): Livestock’s long shadow – environmentalissues and options. FAO, Rome.

UN (2003): State of world population. United Nations Population Fund. New York, www.unfpa.org

Verstegen, M., Tamminga, S. (2006): Feed composition and environmental pollution. In: Recent Developments in Non-ruminant Nutrition, Ed. by P.C. Garnsworthy and J. Wisemann, Nottingham Univ. Press, 453-465.

Waterlow, J.C. (2001): Protein requirements. Progress in Knowledge in the last year. Ann. Nutr. Metab. 45: 200 (Abstr.)

Weizsäcker, E.U. v., A.B., Lovins, and L.H. Lovins (1997): Faktor Vier. Doppelter Wohlstand – halbierter Naturverbrauch.Droemersche Verlagsanstalt Th. Knaur Nachf., München, 352 p.

Wennemer, H., Flachowsky, G., Hoffmann, V. (2005): Protein, Population, Politics – How protein can be supplied sustainablein the 21st Century. Plexus Verlag, Miltenberg und Frankfurt/Main, Hard cover, 160p., ISBN 3-937996-03-6

Young, V.R. (2001): Progress in establishing requirements for amino acids in healthy adults and in disease states. Ann.Nutr. Metab. 45, 200 (Abst.)

Prof. Dr. G. FlachowskyInstitute of Animal NutritionFederal Agricultural Research CentreBundesallee 5038116 Braunschweig, Germany


Preventing Salmonella infectionsby rationally designed feed additives: the use of organic acids

Filip Van ImmerseelGhent University, Merelbeke, Belgium

Introduction

Poultry meat and eggs are important food products and the poultry-related industry is an economicallyimportant component of the agro-industry in the EU. The industry however is under pressure andfaces many challenges. Most importantly, there is a demand for eggs and meat of high nutritionalvalue and free of microbiological and chemical hazards. Unfortunately poultry eggs and meat are oneof the major sources of food borne bacterial infections in humans. In this respect, Salmonella (mainlySalmonella Enteritidis) and Campylobacter are of particular importance, since these pathogens cancolonize the chicken host without causing discernible illness in the infected chickens.

In Europe and the USA, Salmonella Enteritidis has become by far the most important egg-associatedpathogen resulting in a pandemic of non-typhoidal salmonellosis in humans. Despite the recentdecrease in human Salmonella Enteritidis infections due to the introduction of control measures inlayer flocks, Salmonella still is one of the most important bacterial foodborne infections in the world.Serotypes other than Enteritidis are not decreasing in prevalence to the same magnitude as Enteritidis.

While some serotypes, such as Derby and Typhimurium, can be traced back to porcine meat, otherserotypes, such as Virchow, Infantis, Hadar and again Typhimurium, can be traced back to poultrymeat. Since poultry meat will, due to EU legislation, not be brought as fresh poultry meat on themarket from 12/12/2010 if Salmonella is detected, the broiler industry needs to take measures todecrease the colonization of the animals and their environment.

These include pre-harvest, harvest and post-harvest measures. All of these are equally importantand each type of measure has a more or less important effect on reducing the Salmonella incidence,but no measure is successful on its own. Harvest measures are essentially hygienic measures duringcatching and transport, while post-harvest measures include both hygienic measures and the applicationof decontaminating treatments on the meat.

However, all carcass disinfectants are prohibited in the European Union at present, thus decont-amination is not an option. Therefore, prevention and monitoring/eradication during the live phase(pre-harvest) are of great importance in Europe. Pre-harvest prevention and control measures startin dedicated feed mills and on the grandparent farms of primary breeders (MacLeod, 2002) andinclude preventive hygienic measures as well as physical and chemical decontamination treatmentsof feed, drinking water and the environment of the birds down to the commercial farms of broilergrowers and egg producers. Since antibiotics are not the method of choice to control Salmonella andsince vaccination cannot be applied in broilers due to the short life span of the animals, the use offeed additives is more and more accepted as a valuable way to combat bacterial gut infections.Currently however there are numerous products on the market and it is not easy for poultry producersto objectively choose products with proven activity against Salmonella, since most of the productsare empirically produced.

The use of organic acids against Salmonella

A) Effects of short-chain fatty acids on survival and virulence of Salmonella in vitro

Medium chain fatty acids (C6 to C12; caproic, caprylic, capric and lauric acid) appear to be muchmore effective against Salmonella than the short-chain fatty acids (formic, acetic, propionic and butyricacid). As little as 25mM C6 to C10 acids were bacteriostatic to a Salmonella Enteritidis strain, whilethe same strain tolerated 100mM of short-chain fatty acids (Van Immerseel et al., 2003, 2004a). WhenSalmonella Enteritidis and Typhimurium were incubated with low concentrations of monocaprin (5 mM)

Preventing Salmonella infections by rationally designed feed additives: Vol. 42 (1), April 2007, Page 10

that had been combined with an emulsifier, the bacteria did not survive (Thormar et al., 2006). Ingeneral, these data indicate that medium chain fatty acids have the greatest antibacterial activityagainst Salmonella, but large scale studies are lacking.

Salmonella is an opportunistic intracellular pathogen that has an elaborate set of virulence genes.These genes enable the bacterium to adapt to the environment and move between various micro-niches within a host. An early step in the pathogenesis of Salmonella is the penetration of intestinalepithelium.

This activity is promoted by invasion genes that are located on a pathogenicity island (SPI-1), butseveral pathogenicity islands are required for full virulence. SPI-1 has genes encoding regulatoryproteins, structural components of a needle complex and additional effector proteins. Bacterial effectorproteins facilitate the entry of Salmonella into the cytosol of epithelial cells, by inducing actinrearrangements that lead to uptake of the bacteria. SPI-1 is in turn activated by HilA, and this latterprotein is environmentally regulated. When Salmonella Typhimurium was pre-incubated in growthmedia supplemented with various concentrations of butyrate and propionate, epithelial cell invasionwas suppressed (Van Immerseel et al., 2003). However, if the bacteria were preincubated in mediasupplemented with acetate invasion was still observed.

Similar results were obtained with Salmonella Enteritidis when primary caecal epithelial cells of thechicken were employed. The effects of organic acids on epithelial invasion can be explained bychanges in SPI-1 expression. When HilA and invF (major activators of SPI-1) expression was measuredin S. Typhimurium after exposure to acetate, butyrate and propionate at pH 6, exposure of the bacteriato acetate increased the expression of these genes, but similar effects were not observed withpropionate or butyrate (Durant et al., 2000).

More recently, it was shown that butyrate and propionate, but not acetate led to a decrease in hilA, invFand sipC expression (Lawhon et al., 2005) DNA microarrays of both Salmonella Typhimurium andSalmonella. Enteritidis indicated that low doses of butyric acid downregulated SPI-1, but it did notalter metabolic gene expression (Gantois et al., 2006). The primary target of butyrate in the bacte-rial cell is still unknown but butyrate could interfere with HilA dependent regulation of SPI1 by alteringthe regulation of hilD transcription. These data indicate that short-chain fatty acids can regulate the inva-sive phenotype of Salmonella.

B) Effects of short-chain fatty acids in Salmonella control in vivo

The use of acidic compounds to control Salmonella first appeared in the late 1960’s, and mainlyfocused on decontamination of bone meal. Evaluation of the efficacy of 32 different acid preparationsto decontaminate bone meal showed that low molecular weight volatile fatty acids were the mostpromising (Khan and Katamay, 1969). These results were a basis for the development of non-toxic,naturally occurring acidic compounds to control Salmonella. More than 35 years later, it is clear thattheir thoughts were prophetic. These acids have been added to feed, drinking water, and othermatrices, in order to prevent Salmonella colonization of animal tissue and transmission through the foodchain.

Poultry feed is a major source for Salmonella introduction to the farm. When chickens are givenartificially contaminated feed, the gut is colonized and Salmonella are shed into the environment. Theoriginal concept of incorporating acids into feed was based on the notion that the acids woulddecontaminate the feed itself and prevent Salmonella uptake by the chickens.

When Iba and Berchieri (1995) inoculated feed with high doses of a S. Typhimurium strain, a commercialmixture of formic and propionic acid decreased the viability more than 1000-fold over 7 days. Whenbroiler chicks were given the acid treated feed that had been mixed with either Salmonella Enteritidis,Typhimurium or Agona, the caecal Salmonella numbers were 7 logs lower than control animals atday 5 (102 versus 109 cfu/g). Mixtures of formic and propionic acid were also effective when feedwas artificially inoculated with low doses of S. kedougou, and the decrease was most obvious afterseveral weeks of storage. In a large scale study, the number of Salmonella positive breeder feedsamples decreased from 4.1 to 1.1% after the feed was supplemented with 0.5% formic acid. The


antibacterial activities of organic acids were dependent on the temperature and moisture. Since thewater content of poultry feed is generally low, the action of the acids is not always optimal, and it is notclear whether effects of the acids in the feed itself or effects of the acids in the gastrointestinal tractof the animals were the major reason of protection.

In the 1980’s, it became clear that the acid concentrations were also increased in the crop, and thisantibacterial action could aid in controlling infection caused by horizontal transmission. Indeed, whenthe acid treated feed is eaten by the chickens, it is both warmed and moistened and the activity ofthe short chain fatty acids should increase. It appears that supplemental acids are most apt to affectin the crop and gizzard rather than in the intestine. This point is illustrated in a study of Thompsonand Hinton (1997), who fed laying hens a feed supplemented with a commercial mixture of formicand propionic acid. In these animals, pH values of the crop, gizzard, jejunum, caecum and colon werenot altered relative to control animals, but formic and propionic acid concentrations in crop and gizzardwere significantly increased. At the same time, the lactic acid concentration in the crop decreasedsignificantly, suggesting that lactobacilli were either inhibited or killed.

Later in the 1980’s, many studies examined the effects of supplementing acids on Salmonellacolonization of chicken tissues. Mainly the action of formic and propionic acids was tested. In a small-scale field trial, formic acid controlled shedding and caecal colonization by Salmonella serovars innaturally infected the animals. Indeed, 50% of all control animals had Salmonella positive cloacalswabs and caecal content samples, but Salmonella could not be detected in animals that consumedsignificant concentrations of formic acid (Hinton et al., 1985).

In a 3 year study, the cumulative number of infections of newly hatched chicks with Salmonelladecreased after breeder stocks were given formic acid treated feed (Humphrey and Lanning, 1988).Breeders that received acidified feed shed lower numbers of Salmonella in the litter (4.3 versus 1.4%),hatchery waste (15.3 versus 1.2%) and insert paper samples (4.6 versus 1.4%). These decreaseswere evident from the moment the breeders received acidified feed and illustrate the effects of verticaltransmission.

The most striking proof of the efficacy of formic and propionic acid as feed additives to controlSalmonella was given by Hinton and Linton (1988). In three independent experiments, only naturalinfections were monitored. Formic and acetic acid supplemented feed, given from the day of hatch,decreased the number of positive faeces and caecal content samples dramatically. The control groupshad 25, 27 and 60% Salmonella positive faecal samples, but the treatment groups were 3, 0 and 0%.When the formic acid treated feed was given at later age (16 or 32 days), no differences were detectedbetween control and treated groups. This illustrates that preventing initial colonization of Salmonellais most important. Once an infection is established, it is very difficult to counteract by using acid treatedfeed, at least in the same production round.

Recently, researchers have attempted to transport the organic acids further down in the gastrointestinaltract by micro-encapsulation, which should prevent absorption of the acids in the upper tract andensure release further down in the gastro-intestinal tract. Van Immerseel et al. (2004b) examined theeffect of microbeads containing formic, acetic, propionic and butyric acid on colonization of S. Enteritidisin caeca, liver and spleen. Animals were infected (day 5 post-hatch) with 5 x 103 cfu S. Enteritidisand samples were taken 3 days post-infection. Cecal colonization was significantly increased whenacetic acid was added to the feed, but decreased when butyric acid was added (Table 1). Internalorgan colonization was increased if either formic or acetic acid were added to the feed, and this resultis consistent with the idea that acids can enhance the virulence of Salmonella.

When powder and coated butyric acid additives (0.63 g/kg butyric acid) were compared using thesame infection protocol, the coated form decreased colonization of the caeca, but the powdered formdid not (Table 2). The inability of the powered form to give a positive response may have been due tothe short time interval between infection and sampling. In an infection study using a seeder model inwhich 10 broilers were infected at day 5 post-hatch with 105 cfu S. Enteritidis and housed togetherwith 40 non-inoculated broilers, 0.63 g/kg coated butyric acid in the feed significantly reduced shed-ding of S. Enteritidis in broilers until slaughter age (Van Immerseel et al., 2005, (Figure 1)). The effectof the acids on other members of the microbial community was not determined.


Increasing caecal butyrate concentration to control Salmonella: use of pre- and probioticapproaches?

Feed and drinking water sanitation, and the addition of acids to the crop appears to prevent pathogencolonization in the live animals, but the type of acid and its concentration can be very important.Salmonella colonization of the caeca and internal organs is not always affected by these treatments,especially if the infection pressure is high. Acids from feed or drinking water are not effective furtherdown in the intestinal tract because Salmonella colonization is mainly in the caeca. Because thecaecum is the main fermentation site, the concentrations of short-chain fatty acids are already higherthere than in other intestinal segments. It has already been shown in various animal species that


Table 1. Colonization of the caeca at day 8 of life (inoculation with 103 cfu S. Enteritidis76Sa88 on day 5 and 6) in chickens fed a diet supplemented with formic, acetic,propionic and butyric acid or no feed additives.

* Number of chickens in a group of 20 that has a given amount of Salmonella bacteria in the caeca.A,B,C Groups with different superscripts are significantly different.

CTRLA

(n=20)FORA

(n=20)ACEB

(n=20)PROPAC

(n=20)BUTC

(n=20)

Negative 0* 0 0 0 0

Positive after enrichment 6 1 1 8 11

10² < x < 10³ cfu/g 0 1 1 1 2

103 < x < 104 cfu/g 0 4 0 1 1

104 < x < 105 cfu/g 3 2 0 2 3

105 < x < 106 cfu/g 2 2 2 1 3

106 < x < 107 cfu/g 8 7 3 3 0

More than 107 cfu/g 1 3 13 4 0

Table 2. Colonization of the caeca at day 8 of life (inoculation with 106 cfu S. Enteritidis76Sa88 on day 5) in chickens fed a diet supplemented with butyric acid in powderform, coated form, a combination of half doses of powder and coated form (COMBI),or no feed additives (CTRL). Concentration of the active product butyric acid was0.63 g/kg feed in each group.

CTRLA

(n=25)POWDERA

(n=25)COATEDB

(n=25)COMBIB

(n=25)

Negative 0* 0 2 1

Positive after enrichment 6 8 12 8

x < 104 cfu/g 2 1 3 2

104 < x < 105 cfu/g 3 1 0 6

105 < x < 106 cfu/g 4 3 4 5

More than 106 cfu/g 10 12 4 3


0

10

20

30

40

50

60

70

80

90

100

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42

age

% p

ositi

ve a

fter e

nric

hmen

t

*

*

**

* *

unsupplementedfeed (control)

feed supplementedwith coated butyricacid (0.63 g/kgbutyric acid)

* significant differ-ences betweengroups

Figure 1. Number of positive cloacal swabs over time (age) following infection of 10 chickswith 105 cfu S. Enteritidis 76Sa88 at day 5 post-hatch and housing them with 40non-inoculated broilers

Salmonella colonization of the gut is decreased when the bifidobacterial population is increased,either by administration of bifidobacteria as probiotic strains, or by addition of certain types ofoligosaccharides that stimulate proliferation of these bacteria in the gut (Asahara et al., 2001; Buddingtonet al., 2002; Bovee-Oudenhoven et al., 2003; Silva et al., 2004; Thitaram et al., 2005).

Increases in lactic acid bacterial counts in the gut are correlated with increases in butyric acidconcentrations, and Salmonella colonization is decreased when butyric acid levels in the gut areincreased. Bifidobacteria increase butyric acid concentrations, but these bacteria do not producebutyric acid themselves. Lactic acid bacteria, such as lactobacilli and bifidobacteria, stimulate proliferationof butyric acid producing bacteria. This mechanism is called cross-feeding.

It has been shown that lactic acid, produced in vitro by Bifidobacterium adolescentis with starch as solecarbon source, is used by Anaerostipes caccae and Eubacterium hallii (in co-culture) for the productionof high concentrations of butyric acid. Another approach would be a direct stimulation of butyric acidproducing bacteria. In human gut samples, butyric acid producers are anaerobic bacteria belongingto the phylogenetic Clostridium clusters IV and XIVa, and species related to Roseburia, Eubacterium,Faecalibacterium and Coprococcus can also produce butyrate (Pryde et al., 2002; Duncan et al.,2004). Many of the butyrate producing microbiota that are identified are net consumers of acetate.Random cloning and sequencing of 16SrDNA sequences isolated from chicken caeca revealed morethan 85% of the clones belonging to eubacteria and clostridia (Bjerrum et al., 2006). Approximately 10%of the clones had high similarity with Faecalibacterium prausnitzii, a species that produces butyricacid in the human gut.

When butyric acid producing bacteria from poultry caeca were isolated (producing more than 10mMin culture) in the author’s lab, 16SrDNA sequence analysis showed that these isolates were ratherclosely related to the butyrate producing species described for humans. The isolates consumedacetate and produced butyrate, and are most likely also cross-fed by lactate. These data can open newopportunities for Salmonella control. Indeed, increasing the concentration of these butyrate producersin poultry caeca using nutritional strategies and addition of pro- or prebiotics would be an efficientway to combat Salmonella infections.

Chances of success are increased, since these bacteria produce butyric acid at the site whereSalmonella is predominantly colonizing and invading. Furthermore, after years of adding feed additives

to poultry feed in an empirical way, the approach could finally be more rational, aiming at an increasein the butyrate producing flora in chicken caeca, finally providing a way to measure the action of theadditives. The criteria for Salmonella control thus would be: do the additives increase the amountand distribution of butyrate producing bacteria in chicken caeca?

Currently tests are being developed to quantify the presence of the key enzyme involved in butyratesynthesis in the anaerobic butyrate producing flora at the DNA level, in order to produce a simpleand reliable test to evaluate the effect of additives and Salmonella control, even without performing largescale infection trials. This would enable us to rationally design feed additives in the future.

Summary

Acidification of drinking water and feed has been used for years in poultry to control Salmonella. Fordrinking water and powder form feed supplementation, the choice of the acids used is dependent onits ability to kill bacteria. Currently also coated or impregnated acid products are on the market, aimingto bring the acids further down in the gastro-intestinal tract. It was shown that supplementation ofacetic acid coated products to the feed increases colonization of the chicken gut by Salmonella, andthat coated propionic and butyric acid products decreases colonization of the chicken intestinal tract.Moreover, it was shown that coated butyric acid decreased faecal shedding in a seeder model inbroilers throughout the rearing period up to slaughter age. This can be linked with effects of the acidson Salmonella virulence, since exposure of Salmonella to low concentrations of acetic acid increasesinvasion of Salmonella in intestinal epithelial cells, while propionic and butyric acid decrease inva-sion at non growth inhibitory concentrations. This is due to changes in virulence gene expression ofthe genes of the Salmonella Pathogenicity Island I, necessary for invasion. Currently the approachof increasing butyric acid producing gut microbiota is under research in different institutes. Increasingthe concentration of butyrate producers in poultry caeca using nutritional strategies and addition ofpro- or prebiotics would be an efficient way to combat Salmonella infections. Indeed, these bacteriaproduce butyric acid at the site where Salmonella is predominantly colonizing and invading, i.e. thecaeca. Furthermore, after years of adding feed additives to poultry feed in an empirical way, theapproach could finally be more rational, aiming at an increase in the butyrate producing flora in chickencaeca.

Zusammenfassung

Kontrolle von Salmonella Infektionen durch gezielten Einsatz von organischen Säurenim Futter

Seit Jahren wird versucht, mit einer Erhöhung des Säuregrades im Trinkwasser oder Futter Salmonellain den Griff zu bekommen. Für Trinkwasser und Futterzusätze in Pulverform kommt es auf die richtigeWahl der Säuren nach ihrer bakteriziden Wirksamkeit an. Gegenwärtig sind auch beschichtete bzw.imprägnierte Produkte auf dem Markt, die die Säure möglichst tief in den Darmtrakt bringen sollen.

Es konnte gezeigt werden, dass der Futterzusätze mit beschichteter Essigsäure die Darmbesiedlungvon Broilern mit Salmonella fördert, während der Zusatz von Produkten mit Propionsäure undButtersäure die Besiedlung hemmt. Weiterhin konnte nachgewiesen werden, dass der Zusatz vongeschützter Buttersäure nach gezielter Infektion die Ausscheidung von Salmonella im Kot währendder gesamten Mastdauer bis zur Schlachtung signifikant verringerte. Das kann damit zusammenhängen, dass verschiedene Säuren die Virulenz von Salmonellaunterschiedlich beeinflussen, denn geringe Konzentration von Essigsäure fördert das Eindringen vonSalmonella in die Epithelzellen des Darms, während Propionsäure und Butttersäure in nichtwachstumshemmender Konzentration die Besiedlung hemmt. Dies erklärt sich aus Veränderungen derVirulenzexpression der Gene der Salmonella Pathogenitätsinsel I, die für die Invasion notwendigsind.

Gegenwärtig beschäftigen sich verschiedene Institute mit der Frage, wie die Produktion von Buttersäurein der Darmflora erhöht werden kann. Wenn es gelänge, durch Futterzusätze von Pro- bzw. Praebiotica


die Konzentration von Buttersäure produzierenden Bakterien im Blinddarm zu erhöhen, dann wäredas ein effizienter Beitrag werden, um Salmonella Infectionen über das Futter zu bekämpfen. DieseBakterien produzieren Buttersäure da, wo Salmonella überwiegend kolonisieren and eindringen,nämlich im Blinddarm. Nachdem jahrelang Futterzusätze empirisch verabreicht wurden, könnte sichdie gezielte Vermehrung von Buttersäure produzierenden Bakterien im Blinddarm von Hühnern alsrationeller erweisen.

References

Asahara, T., Nomoto, K., Shimizu, K., Watanuki, M. and tanaka, R. (2001). Increased resistance of mice to Salmonellaenterica serovar Typhimurium infection by symbiotic administration of Bifidobacteria and transgalactosylatedoligosaccharides. Journal of Applied Microbiology 91, 985-996.

Bjerrum, L., Engberg, R.M., Leser, T.D., Jensen, B.B., Finster, K. and Pedersen, K. (2006). Microbial community compositionof the ileum and cecum of broiler chickens as revealed by molecular and culture-based techniques. Poultry Science 85,1151-1164.

Bovee-Oudenhoven, I.M., Ten Bruggencate, S.J., Lettink-Wissink, M.L., Van Der Meer, R. (2003). Dietary fructo-oligosaccharides and lactulose inhibit intestinal colonisation but stimulate translocation of Salmonella in rats. Gut 52,1572-1578.

Buddington, K.K., Donahoo, J.B. and Buddington, R.K. (2002). Dietary oligofructose and inulin protect mice from entericand systemic pathogens ant tumor inducers. Journal of Nutrition 132, 472-477.

Duncan, S.H., Holtrop, G., Lobley, G.E., Calder, A.G., Stewart, C.S. and Flint, H.J. (2004). Contribution of acetate to butyrateformation by human faecal bacteria. British Journal of Nutrition 91, 915-923.

Durant, J.A., Corrier, D.E. and Ricke, S.C. (2000). Short-chain volatile fatty modulate the expression of the hilA and invFgenes of Salmonella Typhimurium. Journal of Food Protection 63, 573-578.

Hinton, M. and Linton, A.H. (1988). Control of Salmonella infections in broiler chickens by the acid treatment of their feed.The Veterinary Record 123, 416-421.

Hinton, M., Linton, A.H., and Perry, F.G. (1985). Control of Salmonella by acid disinfection of chicks’ food. The VeterinaryRecord 116, 502.

Humblot, C., Bruneau, A., Sutren, M., Lhoste, E.F., Dore, J., Andrieux, C. and Rabot, S. (2005). Brussels sprouts, inulinand fermented milk alter the faecal microbiota of human microbiota-associated rats as shown by PCR-temporal temperaturegradient gel electrophoresis using universal, Lactobacillus and Bifidobacterium 16S rRNA gene primers. British Journalof Nutrition 93, 677-684.

Humphrey, T.J. and Lanning, D.G. (1988). The vertical transmission of Salmonella and formic acid treatment of chickenfeed. Epidemiology and Infection 100, 43-49.

Iba, A.M. and Berchieri, A. (1995). Studies on the use of a formic acid-propionic acid mixture (Bio-Add™ ) to controlexperimental Salmonella infection in broiler chickens. Avian Pathology 24, 303-311.

Khan, M. and Katamay, M. (1969). Antagonistic effects of fatty acids against Salmonella in meat and bone meal. AppliedMicrobiology 17, 402-404.

Lawhon, S.D., Maurer, R., Suyemoto, M and Altier, C. (2002). Intestinal short-chain fatty acids alter Salmonella Typhimuriuminvasion gene expression and virulence through BarA/SirA. Molecular Microbiology 46, 1451-1464.

Pryde, S.E., Duncan, S.H., Hold, G.L., Stewart, C.S. and Flint, H.J. (2002). The microbiology of butyrate formation in thehuman colon. FEMS Microbiology Letters 217, 133-139.

Thitaram, S.N., Chung, C.H., Day, D.F., Hinton, A.Jr., Bailey, J.S., Siragusa, G.R. (2005). Isomaltooligosaccharides increasescecal Bifidobacterium population in young broiler chickens. Poultry Science 84, 998-1003.

Thompson, J.L. and Hinton, M. (1997). Antibacterial activity of formic and propionic acids in the diet of hens on Salmonellasin the crop. British Poultry Science 38, 59-65.

Thormar, H., Hilmarsson, H. and Bersson, G. (2006). Stable concentrated emulsions of the 1-monoglyceride of capric acid(monocaprin) with microbicidal activities against the food-borne bacteria Campylobacter jejuni, Salmonella spp., andEscherichia coli. Applied and Environmental Microbiology 72, 522-526.

Gantois, I., Ducatelle, R., Pasmans, F., Haesebrouck, F., Hautefort, I., Thompson, A., Hinton, J.C. and Van Immerseel, F.(2006). Butyrate specifically down-regulates Salmonella pathogenicity island I gene expression. Applied and EnvironmentalMicrobiology 72, 946-949.


MacLeod, H. (2002). Practical experience of feed decontamination from breeder’s perspective. Lohmann InformationInternational 26, 7-8.

Silva, A.M., Barbosa, F.H., Duarte, R., Vieira, L.Q., Arantes, R.M. and Nicoli, J.R. (2004). Effect of Bifidobacterium longumingestion on experimental salmonellosis in mice. Journal of Applied Microbiology 97, 29-37.

Van Immerseel, F., De Buck, J., Meulemans, G., Pasmans, F., Velge, P., Bottreau, E., Haesebrouck, F. and Ducatelle, R.(2003) Invasion of Salmonella Enteritidis in avian intestinal epithelial cells in vitro is influenced by short-chain fatty acids,International Journal of Food Microbiology, 85, 237 – 248.

Van Immerseel, F., De Buck, J., Boyen, F., Bohez, L., Pasmans, F., Volf, J., Sevcik, M., Rychlik, I., Haesebrouck, F. andDucatelle, R. (2004a). Medium-chain fatty acids decrease colonization and invasion shortly after infection with SalmonellaEnteritidis in chickens through hilA suppression. Applied and Environmental Microbiology 70, 3582-3587.

Van Immerseel, F., Fievez, V., De Buck, J., Pasmans, F., Martel, A., Haesebrouck, F. and Ducatelle, R. (2004b).Microencapsulated short-chain fatty acids in feed modify colonization and invasion early after infection with SalmonellaEnteritidis in young chickens. Poultry Science 83, 69-74.

Van Immerseel, F., Boyen, F., Gantois, I., Timbermont, L., Bohez, L., Pasmans, F., Haesebrouck, F. and Ducatelle, R.(2005). Supplementation of coated butyric acid in the feed reduces colonization and shedding of Salmonella in poultry.Poultry Science 84, 1851-1856.

Filip Van ImmerseelGhent UniversityFaculty of Veterinary MedicineDepatment of Pathology, Bacteriology and Avian DiseasesSalisburylaan 1339820 MerelbekeBelgium


Control of Salmonella and other zoonotic agentsin the European Community

– current status of legislation –

Matthias VossVeterinary Laboratory, Lohmann Tierzucht, Cuxhaven

Introduction

For the Commission of the European Communities the protection of human health against diseasesand infections transmissible directly or indirectly between animals and humans (zoonoses) is ofparamount importance. This will be a major issue until complete implementation of „Regulation (EC)No 2160/2003 of the European Parliament and of the Council of 17 November 2003 on the controlof salmonella and other specified food-borne zoonotic agents“ in 2013.

In 1992, the European Union adopted a directive to monitor and control Salmonella infections inbreeding flocks of domestic fowl (Council Directive 92/117/EC of 17 December 1992 concerningmeasures for protection against specified zoonoses and specified zoonotic agents in animals andproducts of animal origin in order to prevent outbreaks of food-borne infections and intoxication’sprovided for the establishment of monitoring systems for certain zoonoses and controls on salmonellain certain poultry flocks.) This directive laid down specific minimum measures to control infectionswith Salmonella enteritidis and Salmonella typhimurium in breeding stocks of Gallus gallus.

In recent years, the Scientific Committee on Veterinary Measures relating to Public Health consideredthat the measures in place to control food-borne zoonotic infections were insufficient at that time. Itfurther considered that the epidemiological data collected by Member States were incomplete andnot fully comparable.

As a consequence, the Committee recommended to improve the existing control systems for specificzoonotic agents and in November 2003 the following legislation was implemented for

• the monitoring of zoonoses: Directive 2003/99/EC of the European Parliament and of the Councilof 17 November 2003 on the monitoring of zoonoses and zoonotic agents, amending CouncilDecision 90/424/EEC and repealing Council Directive 92/117/EEC, replacing the monitoring and datacollection systems established by Directive 92/117/EEC, and

• for the control of zoonoses: Regulation (EC) No 2160/2003 of the European Parliament and of theCouncil of 17 November 2003 on the control of salmonella and other specified food-borne zoonoticagents. This Regulation covers the adoption of targets for the reduction of the prevalence of spec-ified zoonoses in animal populations at the level of primary production.

The purpose of Regulation (EC) No 2160/2003 is to ensure that proper and effective measures are takento detect and control salmonella and other zoonotic agents at all relevant stages of production,processing and distribution, particularly at the level of primary production, in order to reduce theirprevalence and the risk they pose to public health. The Regulation covers:

• the adoption of targets for the reduction of the prevalence of specified zoonoses

• the approval of specific control programs established by Member States

• the adoption of specific rules concerning certain control methods

• the adoption of rules concerning intra-Community trade and imports

Therefore, Regulation (EC) No 2160/2003 and especially it’s Annex I, is the basis for the co-ordi-nated control of zoonoses (Salmonella at the moment) within the European Community and gives adetailed time frame in which the prevalence have to be evaluated, targets have to be established andnational control programs have to be prepared, approved by the European Community and imple-mented (see Table 1).

Control of Salmonella and other zoonotic agents in the European Community Vol. 42 (1), April 2007, Page 18

Table 1: Annex 1 of Regulation (EC) No 2160/2003, specified with dates and targets alreadydefined

1. Breeding flocks of Gallus gallus:

1.1 Prevalence study

Based on the data collection in accordance with Council Directive 92/117/EC the data from the year2004 have been used as a basis for the prevalence estimation of Salmonella in breeding flocks ofGallus gallus in the member states. The report on results of monitoring / control of salmonella inbreeding flocks of Gallus gallus in the European Union and Norway (Sanco/1143/2005) shows, thatover all production lines and age groups the prevalence of Salmonella enteritidis in the EuropeanUnion is 1,5 % and for Salmonella typhimurium is 0,2 %. For the “Top 5” (S. enteritidis, S. hadar, S.infantis, S. typhimurium and S. virchow) the prevalence is 2.8 %, varying from 0.0 to 28.0 %. Theprevalence rates of the Top 5 Salmonella serotypes in the Member States is shown in Figure 1.

1.2 Targets for the reduction of Salmonella

On 30 June 2005 Commission Regulation (EC) No 1003/2005 implementing Regulation (EC) No2160/2003 as regards a Community target for the reduction of the prevalence of certain salmonellaserotypes in breeding flocks of Gallus gallus and amending Regulation (EC) No 2160/2003 wasimplemented. For a transitional period of three years the Community target for breeding flocks ofGallus gallus covers the five most frequent salmonella serotypes in humans, which are Salmonellaenteritidis, Salmonella hadar, Salmonella infantis, Salmonella typhimurium and Salmonella virchow.The target in breeding flocks of Gallus gallus shall be a reduction of the maximum percentage of adultbreeding flocks remaining positive to 1 % or less by 31 December 2009.

The testing scheme to verify the achievement of the Community target is set out in Annex I of theRegulation. This includes Monitoring in breeding flocks by sampling at the initiative of the operatorand official control sampling. At the initiative of the operator sampling shall take place every two weeksin agreement with the competent authority either at the hatchery or the holding.

The Official control sampling depends on the sampling of the operator. If sampling at the initiative ofthe operator takes place at the hatchery:


Zoonosis or zoonoticagent

Animal population Stage of food chain Date by with targetmust be established

Date from whichtesting must take

place

All Salmonellaserotypes with publichealth significance

Breeding flocks ofGallus gallus

Primary production Com. Reg. (EC)1003/2005 Target less

than 1%

01.01.2007


Laying hens Primary production Com. Reg. (EC)1168/2005 Reductionby 10-40% dep. on

prevalence

01.02.2008


Broilers Primary production March/April 2007 Presumably:01.01.2009


Turkeys Primary production March/April 2008 Presumably:01.01.2010


Herds of slaughterpigs

Slaughter March/April 2008 Presumably:01.01.2010


Breeding herds of pigs Primary production March/April 2009 Presumably:01.01.2011

(a) routine sampling every 16 weeks at the hatchery, which shall on that occasion replace the corre-sponding sampling at the initiative of the operator;

(b) routine sampling at the holding on two occasions during the production cycle, the first one beingwithin four weeks following moving to laying phase or laying unit and the second one being towardsthe end of the laying phase, not earlier than eight weeks before the end of the production cycle;

(c) confirmatory sampling at the holding, following detection of relevant salmonella from samplingat the hatchery.

If sampling at the initiative of the operator takes place at the holding, routine sampling shall be carriedout on three occasions during the production cycle:

(a) within four weeks following moving to laying phase or laying unit;

(b) towards the end of the laying phase, not earlier than eight weeks before the end of the productioncycle;

(c) during the production, at any time sufficiently distant from the samples referred to in points (a)and (b).

Type and size of sampling material, examination methods to be used and reporting of results are alsospecified in the Annex.

According to Council Regulation 2160/2003/EC specific requirements concerning breeding flocks ofGallus gallus must be followed. In case results of examined samples indicate the presence of SalmonellaEnteritidis or Salmonella Typhimurium in a breeding flock of Gallus gallus non-incubated eggs from theflock must be destroyed. However, such eggs may be used for human consumption if they are treatedin a manner that guarantees the elimination of Salmonella Enteritidis and Salmonella Typhimuriumin accordance with Community legislation on food hygiene. All birds, including day-old chicks, in theflock must be slaughtered or destroyed so as to reduce as much as possible the risk of spreadingsalmonella. Slaughtering must be carried out in accordance with Community legislation on food


2.3 to 28 (7)2.0 to 2.3 (1)1.9 to 2.0 (1)1.5 to 1.9 (2)1.4 to 1.5 (2)0.4 to 1.4 (2)0.3 to 0.4 (1)0 to 0.3 (7)

EuropeTop 5 Breeding Flocks

Figure 1: Prevalence of the Top 5 Salmonella serotypes in Gallus gallus breeding flocks

hygiene. Products derived from such birds may be placed on the market for human consumption inaccordance with Community legislation on food hygiene. If not destined for human consumption, suchproducts must be used or disposed of in accordance with Regulation No 1774/2002 of the EuropeanParliament and of the Council of 3 October 2002 laying down health rules concerning animal by-pro-ducts not intended for human consumption. Where eggs for hatching from flocks in which SalmonellaEnteritidis or Salmonella Typhimurium is present are still present in a hatchery, they must be destroyedor treated in accordance with Regulation No 1774/2002.

1.3 Rules for certain control methods

According to Commission Regulation (EC) No 1091/2005 of 12 July 2005 implementing Regulation (EC) No2160/2003 of the European Parliament and of the Council as regards requirements for the use ofspecific control methods in the framework of the national programs for the control of Salmonellaantimicrobials shall not be used as a specific method to control salmonella in breeding flocks of Gallusgallus.

However, the use of antimicrobials might be permitted in animals presenting salmonella infection withclinical signs in a way likely to cause undue suffering of the animals, salvaging of valuable geneticmaterial in breeding flocks or on a case by-case basis for purposes other than salmonella control ina flock suspect of salmonella infection.

Live Salmonella vaccines should not be used if the manufacturer does not provide appropriate methodsto distinguish bacteriologically wild-type strains of salmonella from vaccine strains.

Commission Regulation (EC) No 1091/2005 was later repealed and replaced by Commission Regulation(EC) No 1177/2006 (see under II. Laying hens).

1.4 National control program

In order to achieve the Community target established by Commission Regulation (EC) No 1003/2005for the reduction of the prevalence of the top 5 salmonella serotypes in breeding flocks of Gallusgallus each Member State had to establish national control programs for the control of salmonella inbreeding flocks of Gallus gallus. These control programs have been approved by Commission Decision2006/759/EC of 8 November 2006 approving certain national programs for the control of salmonellain breeding flocks of Gallus gallus and have to be applied since 1 January 2007.

2. Laying hens


In order to set the target, comparable data on the prevalence of salmonella in the populations of layinghens in Member States should be available. Such information was not available and therefore aspecial study was carried out in order to monitor the prevalence of salmonella in laying hens duringan appropriate period of time in order to take into account possible seasonal variations (CommissionDecision 2004/665/EC of 22 September 2004 concerning a baseline study on the prevalence ofsalmonella in laying flocks of Gallus gallus).

The Preliminary Report was published on 7 April 2006 by the European Food Safety Authority (EFSA).The study was conducted on large-scale laying hen holdings with at least 1.000 laying hens per flockin a period of 1 October 2004 to 30 September 2005. From each flock five pooled samples of faecesand two pooled samples of dust were collected during the last nine weeks of the production period.

The EU weighted prevalence for salmonella spp. in laying hens was 30.7 %, ranging from 0.0 % incountries like Sweden and Luxembourg to 79.5 % in Portugal. The EU weighted prevalence of layingflocks being positive for S. enteritidis or S. typhimurium or both was 20.3 % ranging again fromcountries with 0.0 % to 62.5 % in Czech Republic. This demonstrates that in most Member States


the majority of laying hens is infected with either S. enteritidis or S. typhimurium or both. The prevalencerates of S. enteritidis/S. typhimurium in the Member States is shown in Figure 2.

Figure 2: Prevalence of the S.e./S.tm. in Laying hens

2.2 Targets for the reduction

On 31 July 2006 Commission Regulation (EC) No 1168/2006 implementing Regulation (EC) No2160/2003 as regards a Community target for the reduction of the prevalence of certain salmonellaserotypes in laying hens of Gallus gallus and amending Regulation (EC) No 1003/2005 wasimplemented.

The Community target for the reduction of S. enteritidis and S. typhimurium in adult Laying hens ofGallus gallus depend on the prevalence in the preceding year:

An annual minimum percentage of reduction of positive flocks of adult laying hens equal to at least:

(i) 10 % if the prevalence in the preceding year was less than 10 %;

(ii) 20 % if the prevalence in the preceding year was between 10 and 19 %;

(iii) 30 % if the prevalence in the preceding year was between 20 and 39 %;

(iv) 40 % if the prevalence in the preceding year was 40 % or more;

This target should be achieved in 2008 and is based on the results of the prevalence study carried outunder Decision 2004/665/EC.

The sampling scheme including frequency, sampling protocols, transport of samples, examinationmethods and reporting are specified in the Annex. Sampling shall take place at the initiative of theoperator at least every 15 weeks, starting at the age of 24 ± 2 weeks. Sampling by the competentauthorities shall take place at least in one flock per year per holding or in case of suspicion or detec-tion of S. enteritidis or S. typhimurium.


50 to 62.5 (4)24.3 to 50 (4)8.1 to 24.3 (5)0.4 to 8.1 (5)0 to 0.4 (5)

EuropeSE/ST Laying hens

2.3 Rules for certain control methods

According toCommission Regulation (EC) No 1177/2006 of 1 August 2006 implementing Regulation (EC) No2160/2003 of the European Parliament and of the Council as regards requirements for the use ofspecific control methods in the framework of the national programs for the control of Salmonella inpoultry antimicrobials shall not be used as a specific method to control salmonella in poultry.

However, the use of antimicrobials might be permitted in animals presenting salmonella infection withclinical signs in a way likely to cause undue suffering of the animals, salvaging of valuable geneticmaterial in breeding flocks or on a case by-case basis for purposes other than salmonella control ina flock suspect of salmonella infection.

Live Salmonella vaccines should not be used if the manufacturer does not provide appropriate methodsto distinguish bacteriologically wild-type strains of salmonella from vaccine strains. They also shouldnot be used in laying hens during production unless the safety of the use has been demonstrated.At the latest from 1 January 2008 in Member States which did not demonstrate a prevalence below10 % vaccination programs against Salmonella enteritidis shall be applied at least during the rearingperiod to all laying hens.

2.4 National control program

In order to achieve the Community target established by Commission Regulation (EC) No 1168/2006for the reduction of the prevalence of Salmonella enteritidis and Salmonella typhimurium in layingflocks of Gallus gallus each Member State had to establish national control programs for the controlof salmonella. Those had to be submitted to the European Union until 31 December 2006 and shouldbe approved by the mid of 2007. They have to be applied from 1 February 2008.

2.5 Intra-Community Trade, export and import of eggs

The Commission of the European Communities is working on a Commission Regulation introducingrestrictions on the intra-community trade, export and import of eggs from salmonella infected flocksof laying hens (SANCO/1188/).

According to the draft of this Commission Regulation, intra-community trade and export of eggs,classed A in accordance to Regulation (EEC) No 1907/1990 shall only be authorized if derived fromholdings applying the monitoring laid down in the Annex of Regulation (EC) 1168/2006 and whichare not suspected of having or infected by Salmonella enteritidis or Salmonella typhimurium. Importedeggs shall only be authorized if derived from flocks providing similar guarantees as stated in adeclaration by the competent authority of the country of production.

These restrictions for trade will be implemented either from 1 February 2008 or 1 January 2009. Eggsfrom laying hens infected with Salmonella enteritidis or Salmonella typhimurium will result in class Beggs with a “S” identification.

3. Broilers


In order to provide the scientific basis for setting of the Community target for reduction of the prevalenceof salmonella in boiler flocks of Gallus gallus, an European-Union wide study was carried out in orderto determine the prevalence of salmonella in boiler flocks (Commission Decision 2005/636/EC of 1September 2005 concerning a baseline survey on the prevalence of Salmonella spp. in broiler flocksof Gallus gallus).

The Report was published on 28 March 2007 by the European Food Safety Authority (EFSA). Thestudy was conducted on commercial holdings with at least 5.000 birds on the holding in a period of 1


October 2005 to 30 September 2006. From each flock five pooled samples of faeces (by boot swabsor sock samples).

The EU weighted prevalence for salmonella spp. in broilers was 23.7 %, ranging from 0.0 % in Swedento 68.2 % in Hungary. The EU weighted prevalence of broiler flocks being positive for S. enteritidisor S. typhimurium or both was 11.0 % ranging again from countries with 0.0 % to 39.3 % in Portugal.The Community weighted observed flock prevalence for the 5 most frequently reported Salmonellaserotypes was:

• S. enteritidis 10.9 %

• S. typhimurium 0.5 %

• S. infantis 2.2 %

• S. mbandaka 0.4 %

• S. hadar 1.1 %

• Others 6.5 %

The prevalence rates of S. spp. and S. enteritidis/S. typhimurium in broiler flocks in the Member Statesis shown in Figure 3 and 4.

Figure 3: Prevalence of the S. spp. in broiler flocks

3.2 Targets for the reduction

For a transitional 3 year period Regulation (EC) No 2160/2003 foresees the reduction of the Salmonellaprevalence in broiler flocks only for two Salmonella serotypes, S. enteritidis and S. typhimurium, thetwo most frequently reported Salmonella serotypes in human salmonellosis.

As the prevalence study in broilers demonstrates that in most Member States Salmonella serotypesothers than Salmonella enteritidis and Salmonella typhimurium are more frequently found, the targetsmight be extended to other serotypes either by the Member States within their national control programsor after risk-benefit analysis also later by the European Union.

Targets for the reduction of the prevalence of Salmonella enteritidis and Salmonella typhimurium inbroiler flocks are still to be established in April 2007.


43.5 to 68.2 (3)27.6 to 43.5 (3)15.0 to 27.6 (3)7.5 to 15.0 (3)5.4 to 7.5 (4)1.6 to 5.4 (4)0 to 1.6 (4)

EuropeSalm spp Broilers

3.3 National control programs

In order to achieve the Community target for the reduction of the prevalence of Salmonella enteri-tidis and Salmonella typhimurium in broiler flocks of Gallus gallus each Member State have to estab-lish national control programs for the control of salmonella. Those have to be send to the EuropeanUnion until 31 December 2007 and should be approved by the mid of 2008. Presumably they have tobe applied from 1 January 2009.

4. Turkeys

In turkeys, both breeder and meat turkey flocks, the prevalence study started on 1 October 2006and will end on 30 September 2007 (Commission Decision 2006/622/EC of 29 September 2006concerning a financial contribution from the Community towards a baseline survey on the prevalenceof Salmonella in turkeys to be carried out in the Member States). The report on this study is expectedin the beginning of 2008. Targets for the reduction of Salmonella in turkey flocks have to be establisheduntil March / April 2008 and the national control programs have to be sent to the European Unionuntil 31 December 2008.

The approval of national control programs is expected in early 2009 and they should be applied as of1 January 2010, focusing on Salmonella enteritidis and Salmonella typhimurium.

5. Slaughter Pigs

Also in herds of slaughter pigs, the prevalence study started on 1 October 2006 and will end on 30September 2007. The report on this study is expected in the beginning of 2008. Targets for thereduction of Salmonella in slaughter pigs have to be established until March / April 2008 and thenational control programs have to be sent to the European Union until 31 December 2008.

The approval of national control programs is expected again in early 2009 and they should be appliedas of 1 January 2010. On which Salmonella serotypes these control programs have to focus is notclear at the moment and depend on risk-benefit analysis done by the European Union.


Figure 4: Prevalence of the S.e./S.tm. in boiler flocks

28.2 to 39.3 (3)5.1 to 28.2 (3)3.2 to 5.1 (3)1.7 to 3.2 (3)1.0 to 1.7 (4)0.2 to 1.0 (4)0 to 0.2 (4)

EuropeSe/Stm Broilers

6. Breeding pigs

In breeding pigs, the prevalence study will start on 1 October 2007 and will end on 30 September 2008.The report on this study is expected in the beginning of 2009. Targets for the reduction of Salmonellain pig breeding herds have to be established until March / April 2009 and the national control programshave to be sent to the European Union until 31 December 2009.

The approval of national control programs is expected in early 2010 and they should be applied as of1 January 2011. On which Salmonella serotypes these control programs have to focus is again not clearat the moment and depend on risk-benefit analysis done by the European Union.

7. Discussion

The complete implementation of Regulation (EC) No 2160/2003 of the European Parliament and ofthe Council of 17 November 2003 on the control of salmonella and other specified food-borne zoonoticagents will only be achieved in 2013 at the earliest. The current status of implementing this regulationin the primary poultry production is summarized in Table 2.

In breeding flocks of Gallus gallus the Community target for the Top 5 salmonella serotypes shall bea reduction of the maximum percentage of adult breeding flocks remaining positive to 1 % or lessby 31 December 2009. According to the prevalence evaluation in 2004, this Community target wasreached under the conditions of Council Directive 92/117/EC already by 9 Member States. This maychange to some degree as the sampling frame under Commission Regulation (EC) No 1003/2005 ismuch more sensitive as compared to sampling under Council Directive 92/117/EC.

In several countries, this Community target might only be achieved with the intensive use of vaccinesagainst Salmonella. For those Salmonella serotypes of the Top 5, where licensed vaccines are notavailable, the use of autogenous vaccines might be necessary.

In Laying flocks of Gallus gallus the prevalence study has shown that the EU weighted prevalenceof laying flocks being positive for S. enteritidis or S. typhimurium or both was 20.3 %. This meansthat every 5th flock of laying hens in the Community will be affected at the latest when the CommissionRegulation regarding intra-community trade and export of eggs will be in place. These restrictionswill be implemented either from 1 February 2008 or 1 January 2009. Latest from this date, eggs fromlaying hens infected with Salmonella enteritidis or Salmonella typhimurium could not be marketedanymore. This will have dramatic effects for the egg industry.

The prevalence study in broilers has demonstrated that the EU weighted prevalence for salmonellaspp. was 23.7 % and for Salmonella enteritidis or Salmonella typhimurium or both was 11.0 %. Asthe Community target in broilers focus only on Salmonella enteritidis and Salmonella typhimurium,in most Member states the targets to be achieved under Regulation (EC) No 2160/2003 will affectthe prevalence only partially. But on the other hand Annex II (E) of Regulation (EC) No 2160/2003defines specific requirements concerning fresh meat. With the effect from 84 months after entry intoforce of this Regulation (e.g. in 2010), fresh poultry meat from animals listed in Annex I (see table 1)may not be placed on the market for human consumption unless it meets the following criterion:‘Salmonella: absence in 25 grams’. By this criterion the poultry meat industry is not only challengedin regard to the presence of Salmonella enteritidis and Salmonella typhimurium, but must focus onany type of Salmonella.

Although measure related to the implementation of Regulation (EC) No 2160/2003 might be co-financed with 50% by the European Commission this most probably will be handled by the MemberStates completely different depending on methods of compensation and reserve-funds available.Therefore, implementation of Regulation (EC) No 2160/2003 remains and continues to be of majoreconomic importance for the poultry industry in the European Community.

And simultaneous to the control of Salmonella Directive 2003/99/EC of the European Parliament andof the Council of 17 November 2003 on the monitoring of zoonoses and zoonotic agents foreseesalso the control of Campylobacter in poultry. A prevalence study for broilers is in preparation and maystill begin in 2007.


Zusammenfassung

Stand der EU-Gesetze zur Kontrolle von Salmonellen und anderen Zoonosen

Die Europäische Kommission hat sich zum Ziel gesetzt, die Lebensmittelsicherheit in den Mitgliedstaatendurch entsprechende einheitliche Gesetzgebung zu verbessern. Einen hohen Stellenwert hat dabeidie systematische Verringerung von Zoonosen. In einem ersten Schritt wurden 1992 Maßnahmenzur Kontrolle der beiden wichtigsten Salmonellenarten, S. enteritidis und S. typhimurium, inZuchtbeständen festgelegt.


Table 2: REGULATION (EC) No 2160/2203 on the control of Salmonella and other specifiedfood-borne zoonotic agents

Animalpopulation Prevalence Study Community Target Rules for Control

MethodsNational control

programs

Breeding flocksof Gallus gallus

Council Decision92/117/EC

01.01.2004-31.12.2004

Report:SANCO/1143/2005

Top 5: EU weighted

prevalence 2.8%

Comm. Reg.(EC)No 1003/2005Target: Top 5

1 % or less by 31December 2009

Comm. Reg.(EC)No 1091/2005

• No use ofantimicrobials

• Requirementsfor use of livevaccines

Comm. Decision2006/759/EC

• Approval of nati-onal control pro-grams for breedingflocks of Gallusgallus

• To be applied from1 January 2007

Laying hens Council Decision2004/665/EC01.10.2004-30.09.2005

Report: EFSApreliminary report

'Analysis ofSalmonella inlaying hens', 7 April 2006Se/Stm: EU

weightedprevalence

20.3 %


An annual minimumpercentage of reduction

of positive flocks ofadult laying hens equal

to at least:(v) 10 % if the preva-

lence was less than 10 %;

(vi) 20 % if the preva-lence was between10 and 19 %;

(vii) 30 % if the preva-lence was between20 and 39 %;

(viii) 40 % if the prevalencewas 40 % or more;


• No use ofantimicrobials

• Requirementsfor use of livevaccines

• From 1 January2008 vaccinationagainst S. enteri-tidis in countrieswith prevalence> 10 %

• Submitted since 31December 2007

• Approval expectedmid 2007

• To be applied from1 February 2008

Broilers Council Decision2005/636/EC01.10.2005-30.09.2006

Report: EFSAbaseline study onthe prevalence of

Salmonella inbroiler flocksSe/Stm: EU

weighted preva-lence 11.0 %

To be established in April 2007

To be established • To be submitteduntil 31 December2007

• Presumably to beapplied from 1 January 2009

Turkeys Council Decision2006/622/EC01.10.2006-30.09.2007

To be established in March/April 2008

To be established • To be submitteduntil 31 December2008

• Presumably to beapplied from 1 January 2010

Inzwischen wurde der Katalog zu treffender Maßnahmen erheblich erweitert, konkrete Ziele wurdenfür verschiedene Tierarten festgelegt. Derzeit bestehen jedoch noch Unterschiede zwischenMitgliedstaaten in der Prävalenz verschiedener Erregertypen und Maßnahmen zu ihrer Kontrolle. In dieser Übersicht werden die Vorgaben der EU für Hühner, Puten und Schweine (getrennt für Zucht-bzw. Elterntierbestände und Endprodukte) beschrieben. Durch Kennzeichnung der Produkte undHandelsbeschränkungen soll in den kommenden Jahren das Risiko von Salmonellosen in der EUsystematisch reduziert werden. Über die verabschiedeten Maßnahmen zur Kontrolle von Salmonellenhinaus werden entsprechende Maßnahmen gegen Campylobakter vorbereitet.

ReferencesCouncil Directive 92/117/EC of 17 December 1992 concerning measures for protection against specified zoonoses and

specified zoonotic agents in animals and products of animal origin in order to prevent outbreaks of food-borne infectionsand intoxication’s provided for the establishment of monitoring systems for certain zoonoses and controls on salmonellain certain poultry flocks Official Journal of the European Union 1993, L 062/38, 15.03.1993

Directive 2003/99/EC of the European Parliament and of the Council of 17 November 2003 on the monitoring of zoonosesand zoonotic agents, amending Council Decision 90/424/EEC and repealing Council Directive 92/117/EEC Official Journal of the European Union 2003, L 325/31, 12.12.2003

Regulation (EC) No 2160/2003 of the European Parliament and of the Council of 17 November 2003 on the control ofsalmonella and other specified food-borne zoonotic agentsOfficial Journal of the European Union 2003, L 325/1, 12.12.2003

Commission Decision 2004/665/EC of 22 September 2004 concerning a baseline study on the prevalence of salmonellain laying flocks of Gallus gallus Official Journal of the European Union 2003, L 303/30, 30.09.2004

Commission Regulation (EC) No 1003/2005 implementing Regulation (EC) No 2160/2003 as regards a Community targetfor the reduction of the prevalence of certain salmonella serotypes in breeding flocks of Gallus gallus and amendingRegulation (EC) No 2160/2003 Official Journal of the European Union 2005, L 170/12, 01.07.2005

Commission Regulation (EC) No 1091/2005 of 12 July 2005 implementing Regulation (EC) No 2160/2003 of the EuropeanParliament and of the Council as regards requirements for the use of specific control methods in the framework of thenational programs for the control of Salmonella Official Journal of the European Union 2005, L 182/3, 13.07.2005

Commission Decision 2005/636/EC of 1 September 2005 concerning a financial contribution from the Community towardsa baseline survey on the prevalence of Salmonella spp. in broiler flocks of Gallus gallus to be carried out in the MemberStates Official Journal of the European Union 2005, L 228/14, 03.09.2005

EFSA preliminary report ‘Analysis of Salmonella in laying hens’, 7 April 2006

Commission Regulation (EC) No 1168/2006 implementing Regulation (EC) No 2160/2003 as regards a Community targetfor the reduction of the prevalence of certain salmonella serotypes in laying hens of Gallus gallus and amending Regulation(EC) No 1003/2005 Official Journal of the European Union 2006, L 211/4, 01.08.2006

Commission Regulation (EC) No 1177/2006 of 1 August 2006 implementing Regulation (EC) No 2160/2003 of the EuropeanParliament and of the Council as regards requirements for the use of specific control methods in the framework of thenational programs for the control of Salmonella in poultry Official Journal of the European Union 2006, L 212/3, 02.08.2006

Commission Decision 2006/622/EC of 29 September 2006 concerning a financial contribution from the Community towardsa baseline survey on the prevalence of Salmonella in turkeys to be carried out in the Member StatesOfficial Journal of the European Union 2006, L 272/22, 03.10.2006

Commission Decision 2006/759/EC of 8 November 2006 approving certain national programs for the control of salmonellain breeding flocks of Gallus gallus Official Journal of the European Union 2006, L 311/46, 10.11.2006

Commission Regulation introducing restrictions on the intra-community trade, export and import of eggs from salmonellainfected flocks of laying hens (SANCO/1188/2006)

Report of the Task Force on Zoonoses Data Collection on the Analysis of the baseline study on the prevalence of Salmonellain broiler flocks of Gallus gallus, Part A, The EFSA Journal (2007) 98, 1-85


Vol. 42 (1), April 2007, Page 29

Breeder farms and hatchery as integrated operation

Hafez Mohamed HafezInstitute of Poultry Diseases, Faculty of Veterinary Medicine

Free University Berlin, Königsweg 63, 14163 Berlin, Germany

Introduction

The goal of the poultry breeding industry is the production of healthy chicks, which will be viable fromboth an immunological and nutritional perspective, when placed in the production setting.Communication and shared responsibility between the breeder farms and hatchery are essential tominimize the risk and consequences of health problems.

Good rearing management is the starting point for healthy, productive and profitable hatching eggproduction. Rearing management means all factors which influence the birds’ health and includesseveral factors such as house structure, climatic conditions (ventilation, temperature, litter condition),stocking density, feed and water supply, hygienic conditions as well as the qualification and knowledgeof the stockman. These factors affect each other and can promote or inhibit the health condition ofthe flock. In aiming to achieve desired performance results, managers of breeder flocks should integrategood environment, husbandry, nutrition and disease control programs. The rearing management mustbe directed to satisfy the bird’s requirements, to promote the production and to prevent diseases. Anydisturbance can cause stress, which will reduce the resistance of the birds, increase their susceptibilityto infections and reduce their immune response to vaccines.

Infectious poultry diseases are often associated with severe economic losses. Many of these diseases,re-emerging or introduced into a geographic area, can explode into an epidemic and may significantlyaffect international trade. Early recognition and monitoring programs are essential in managinginfections and minimizing their economic impact.

Infectious agents can be introduced into and spread among breeder farms by different routes. Allinfectious agents are transmitted horizontally (laterally) by direct contact between infected and non-infected susceptible birds or through indirect contact with contaminated environments through ingestionor inhalation of organisms. In addition, infections can occur via contamination of feed, water, equipment,environment and dust. Significant reservoirs for micro-organisms are man, farm animals, pigeons,water fowl and wild birds. Rodents, pets and insects are also potential reservoirs and transmit theinfection between houses and can contaminate stored feed. Further sources are “carrier” birds whocontinue to excrete the infectious agent after they recover and no longer show clinical symptoms ofthe disease. Contaminated material can also be picked up on shoes and clothing and carried froman infected to a healthy flock. The disease can be spread by vaccination and beaking trimming crews,manure haulers, drivers of rendering trucks and feed delivery personnel.

Vertical transmission occurs primarily by systemic ovarian transmission, by passage through theoviduct or by contact with infected peritoneum or air sacs. Secondly, vertical transmission happens bycontamination of the egg content as a result of faecal contamination of the eggshell in contaminatednests, floor or incubators with subsequent penetration into the eggs (Fig. 1).

Disease prevention and control

Control measures to prevent introduction and spread of infections in breeder flocks should beconcentrated on high standards of poultry husbandry with bacteriological and serological monitoringof breeding birds. These measures must be coupled with meticulous attention at all stages of hatchingegg production. The general strategy to control infectious poultry diseases includes:

(1) eradication of vertically transmitted diseases from top to bottom – initiated by the primary breederand pursued down to the commercial producer;


Vol. 42 (1), April 2007, Page 30

(2) hatchery hygiene and hatching egg sanitation as well as education programs and regular bacte-riological examination of employees; and

(3) hygienic measures throughout the production chain, vaccination, therapy, decontamination offeed. Efforts of the industry to improve bio-security may be supported or even enforced by legis-lation.

Hygienic measures

It is vital that hygienic standards in the breeder house are impeccable to avoid infection entering thehatchery either within or on the shell of the eggs. The design of the house is usually based on theproduction objective and focused on efficient production of hatching eggs. The design and constructionof breeder houses should also focus on easy management, maintenance, and application of effectivehygienic measures. Poultry houses should be kept locked and no visitors allowed to enter. Furtherprecautions related to staff should be taken. Regular bacteriological examinations must be performedto identify carriers and to prevent transmission and cross contamination on the farm. Cleaning,disinfection and vector control must be integrated in a comprehensive disease control program. Theprocedure should be tailored to meet the particular needs. The cleaning and disinfection programshould include time schedule, type of disinfectant and concentration as well as microbiologicalmonitoring of the procedures. The procedures should be established not only for cleaning anddisinfecting the house and surfaces but also for cleaning and disinfection of the equipment, which isitself used for cleaning. Rodents, especially rats and mice, are particularly important sources ofsalmonella contamination of poultry houses. An intensive and sustained rodent control is essentialand needs to be well planned and routinely performed and its effectiveness should be monitored.Household pets also constitute a serious hazard. Buildings therefore should be pet proof.

In breeder farms it is important to optimize the production of clean fertile hatching eggs, by keepingegg laying areas as clean as possible, including the nest litter or pads. In addition, the breeder housenesting should be inspected on a regular basis. Hatching eggs should be collected frequently (3-4times daily) to minimize the time that they are exposed to a contaminated environment. All substandardeggs with misshapen, cracked or thin shells should be removed. The egg shells should be disinfectedsoon after collection on the farm, since the penetration of the shell by micro-organisms is particularlyrapid. If the bacteria penetrate the shell before the egg reaches the hatchery, it is difficult to find aneffective method to counteract such contamination.

Two methods are used to disinfect hatching eggs under field conditions, namely fumigation or dippingin a solution of detergent or disinfectant. Fumigation is done best with formaldehyde gas for at least20 minutes with a concentration of 35 ml formalin mixed with 17.5 g potassium permanganate and20 ml water per m³ space. Temperature during fumigation must be maintained at a minimum of 20-24°Cand relative humidity at 70%. The eggs should be placed in trays that will permit the fumigant tocontact as much of the shell surface as possible. Because of the unpleasant nature of formaldehydegas and its possible health hazards to the operator, some owners elect to use wet treatments. Different


Figure 1: Some possible egg-borne infections

Systemic Contamination of the eggshell

Avian encephalomyelitisLymphoid leucosisEgg drop SyndromeChicken Infectious AnaemiaSalmonellaMycoplasmaReovirus?

SalmonellaStaphylococcusE. coliPseudomonadsProteus spp.Aspergillus spp.

Vol. 42 (1), April 2007, Page 31

sanitizing solutions are used and most of them are based on chlorine, glutaraldehyde or quaternaryammonium compounds. Egg dipping in detergents or in disinfectants is highly effective in greatlyreducing or eliminating the bacteria from the shell when performed correctly. However, there is littleor no effect on those bacteria that have already penetrated the shell. Manufacturer’s instruction forthe chemicals used should be followed, particularly those concerning the number of eggs that maybe dipped per liter solution and how often fresh solution has to be provided. Attention also must bedirected to the temperature of the detergent which must be higher than the egg temperature. Afterhatching egg sanitation, hygienic measures should be followed to preclude recontamination. Farmegg rooms should have a guideline for cleanliness and standard operation. Bacterial contaminationin the egg room should be routinely monitored.

Vaccination

Vaccination is one of the most effective tools to prevent specific diseases. Several factors are dictatingthe choice of the vaccine, vaccination route and frequency of vaccination. These factors are: theepidemiological situation, the type of production, management practices on the farm, the goal of vacci-nation, availability of the vaccine, cost benefit analysis, general health status of the flock and govern-mental regulations. Vaccination programs for breeder flocks should be tailored to induce long lastinghigh antibody levels during the entire production cycle in order to protect against possible field chal-lenge, to maintain acceptable standards of egg production, egg quality and hatchability, and to transferthe desired maternal antibodies to the offspring.

Treatment

In spite of all precautions, poultry may become sick. In such cases rapid medication is essential.Several drugs have been found useful for reducing clinical signs and shedding of some bacterialdiseases in infected flocks. Treatment should reduce losses, but in some cases relapses may occurwhen treatment is discontinued. No drugs should be given until a diagnosis has been obtained; givingthe wrong drug can be a waste of money. Drugs should be used very carefully: the correct dose leveland duration is important. It should also be kept in mind that residues of drugs in fertile eggs fromtreated breeders may occasionally cause abnormalities in some embryos.

Eradication by industry and legislation

Salmonella

Salmonellosis and salmonella infections in poultry are distributed world-wide and result in severeeconomic losses when no effort is made to control them. The large economic losses are caused byhigh mortality during the first four weeks of age, high medication costs, and reductions in egg productionin breeder flocks, poor chick quality and high costs for eradication and control measures. The mostimportant aspect, however, is the effect of salmonella contaminated eggs, poultry meat and meat-products on public health.

Salmonella belong to the family Enterobacteriaceae and all members are Gram-negative, non-sporingrods without capsules. The genus Salmonella includes about 2500 serovars. Some serovars may bepredominant for a number of years in a region or country, then disappear to be replaced by anotherserovar. The course of the infection and the prevalence of salmonellosis in poultry depend on severalfactors such as: salmonella serovar involved, age of birds, infectious dose and route of infection.Further, stress-producing circumstances such as bad management, poor ventilation, high stockingdensity or concurrent diseases may also contribute to the development of a systemic infection withpossibly heavy losses among young birds. After recovery, birds continue to excrete salmonella intheir faeces. Such birds must be considered as a potential source for transmission of the micro-organisms. The incubation periods range between 2 and 5 days. Mortality in young birds varies fromnegligible to 10 - 20% and in severe outbreaks may reach 80% or higher. The severity of an outbreak


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in young chicks depends on the serovar involved, virulence, degree of exposure, age of birds,environmental conditions and presence of concurrent infections.

If infection was egg transmitted or occurred in the incubator, there will be a lot of unpipped and pippedeggs with dead embryos. Symptoms usually seen in young birds are somnolence, weakness, droopingwings, ruffled feathers and huddling together near heat sources. Many birds that survive for severaldays will become emaciated, and the feathers around the vent will be matted with faecal material.Furthermore respiratory distress as well as lameness as a result of arthritis may be present. Adultbirds serve mostly as intestinal or internal organ carriers over longer periods with little or no evidenceof the infection.

In general the main strategy for control of microbial food borne hazards should include: Cleaning theproduction pyramid from the top (in the case of invasive salmonella) by destroying infected flocks,hatching egg sanitation and limiting introduction and spread at the farm through Good Animal HusbandryPractices. Reducing salmonella colonization by using feed additives, competitive exclusion treatmentor vaccines offer additional possibilities.

In 1992, the European Union adopted a directive to monitor and control Salmonella infections (Directive92/117/EEC) in breeding flocks of domestic fowl. This directive laid down specific minimum measuresto control the infection. Those focused on monitoring and controlling salmonella in breeding flocks ofthe species Gallus gallus, when serotypes Salmonella Enteritidis or Salmonella Typhimurium weredetected and confirmed in samples taken.

The Scientific Committee on Veterinary Measures relating to Public Health considered that themeasures in place to control food-borne zoonotic infections were insufficient at that time. It furtherconsidered that the epidemiological data collected by Member States were incomplete and not fullycomparable. As a consequence, the Committee recommended to improve the existing control systemsfor specific zoonotic agents. Simultaneously, the rules laid down in Directive 2003/99/EC of theEuropean Parliament and of the Council of 17 November 2003 on the monitoring of zoonoses andzoonotic agents, amending Council Decision 90/424/EEC and repealing Council Directive 92/117/EEC,replaced the monitoring and data collection systems established by Directive 92/117/EEC and CouncilRegulation 2160/2003/EC on the control of salmonella and other specified food-borne zoonotic agentswas adopted. This Regulation covers the adoption of targets for the reduction of the prevalence ofspecified zoonoses in animal populations at the level of primary production. After the relevant controlprogram has been approved, food business operators must have samples taken and analyzed to testfor the zoonoses and zoonotic agents. On 30 June 2005 the Commission issued Regulation (EC) No1003/2005 implementing Regulation (EC) No 2160/2003 as regards a Community target for the reduc-tion of the prevalence of certain salmonella serotypes in breeding flocks of Gallus gallus and amendingRegulation (EC) No 2160/2003. The Community target for the reduction of Salmonella Enteritidis,Salmonella Hadar, Salmonella Infantis, Salmonella Typhimurium and Salmonella Virchow in breedingflocks of Gallus gallus shall be a reduction of the maximum percentage of adult breeding flocksremaining positive to 1 % or less by 31 December 2009. Details of European legislation to controlSalmonella and other zoonotic diseases is dealt with in detail by Voss (2007) in this issue of LohmannInformation.

Avian Mycoplasmosis

Mycoplasmas have affected the industry for many years and effective control of Mycoplasma infectionhas been a fundamental stepping-stone to improved performance and productivity. However, infectionsappear to be making a comeback. Numerous species of mycoplasmas have been isolated from aviansources. Two species are recognized as predominantly pathogenic to chickens and turkeys.Mycoplasma gallisepticum (MG) affects the respiratory system and is referred to as chronic respiratorydisease (CRD) in chickens, and infectious sinusitis in turkeys. Mycoplasma synoviae (MS) may causerespiratory and/or joint diseases. Two additional species are known to be pathogenic to turkeys.Mycoplasma meleagridis (MM) causes airsacculitis, and Mycoplasma iowae (MI) causes decreasedhatchability.


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The disease spreads from flock to flock by vertical transmission through infected eggs. Infectedprogeny then transmit the agent horizontally either by direct bird-to-bird contact or by indirect contactthrough contaminated feed, water and equipment. Concerning vertical transmission, hens whichbecome infected before the onset of lay tend to transmit at a lower rate than hens initially infectedduring egg production. Generally egg transmission is intermittent and the rate is variable (1-10%)and very low. The spread of infection from bird to bird within one pen is usually rapid, but it is rarelytransmitted from one house to another. However, in continuous production complexes (multiple-age)with chronic apparently healthy carriers the spread of infection is difficult to control since the cycle ofinfection can not be broken without complete depopulation. The agent also can be transmitted byother species of birds as well as mechanically by other animals and man.

The clinical signs and the course of the disease are influenced by several factors such as the presenceof concurrent micro-organisms (such as TRT, Influenza, Reo and E.coli) and/ or improper management(increased dust and ammonia levels in the environment).

Eradication of Mycoplasma in breeder flocks through testing and slaughter is the preferred method toclean the production chain from the top and to prevent mycoplasma introduction through primary andcommercial breeder flocks. However, in places with intensive continuous poultry production it hasbeen determined that this method is too expensive and impractical. Hatching egg treatments withantibiotics for the control of egg transmitted bacterial pathogens has been widely investigated andseems to be of great value. Different methods of egg treatment have been used such egg dipping inantibiotics using pressure differential dipping or temperature differential dipping. These methodsgreatly reduce the mycoplasma egg transmission, but do not always completely eliminate it.

Dipping solutions can become excessively contaminated with resistant micro-organisms such aspseudomonads and organic material. To prevent bacterial contamination of the solution filtering withsubsequent cool storage and/or addition of disinfectants is the most effective method. Thorough andcontinuous bacteriological monitoring of dip solution is also required. The concentration of the antibioticsmust be examined regularly and renewed routinely. By using enrofloxacin the pH-value of the dippingsolution can be corrected during storage. The use of egg dipping in antimicrobials should be criticallyevaluated, because of the irregular uptake of dip solution, uneven distribution of active substance inthe egg compartments and lack of standardization in dipping technique. Additionally, it is known thatdifferent disinfectants used for washing can influence negatively the antibiotic uptake of hatchingeggs. Therefore it is recommended that the compatibility of different disinfectants used for egg washingand/or used in dipping solution has to be examined before application. As the uptake of active substanceby the hatching egg can be very irregular during dipping, individual egg injection with accurate deliveryof the proper dose is preferred in elite and grandparent breeding stock. Automated systems for inovo drug disposition before hatch can also be used.

Hatchery management

Hatcheries must be designed to permit only a one way flow of traffic from the egg entry room throughegg trays, incubation, hatching and holding rooms to the van loading area. The ventilation systemmust prevent recirculation of contaminated air. Hatching eggs should be from known sources to ensurethat the origin of eggs is traceable. Do not incubate floor eggs, cracked eggs or eggs with hairlines.All eggs should be sanitized on arrival at the hatchery (pre-setting treatment) using fumigation.Additionally fumigation can be carried out after setting. This provides a final disinfection followinghandling, transport and risks of environmental contamination during storage of hatching eggs.

Good hatchery practice includes the analysis of unhatched eggs on a regular basis and, if infectionsare found, to trace the sources. Sanitation in the hatchery is paramount to the future health of chicksand poults. Cleaning and disinfection of machines and rooms must be carried out regularly. Hatcheryequipment must be free of all organic matter before disinfection to ensure that the hatchery sanitationprogram is fully effective. Fluff samples from various surfaces in the hatchery should be cultured to detectmicrobial populations in hatchery air. The health status of all employees, including chick sexers,should be regularly monitored.


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Education programs

The success of any disease control program depends on all people with direct or indirect contact withhatching eggs or chicks. It is essential to incorporate education programs about micro-organisms,modes of transmission as well as awareness of the reasons behind such control programs by peopleinvolved in poultry production.

Conclusions

Disease conditions are mostly accompanied with heavy economic losses in the poultry industry.Breeder farms and hatchery should be considered as an integrated operation. Close communicationbetween breeder farm and hatchery is essential in sharing responsibility. Goals set for hatching eggproduction, hatchability and chick quality can only be reached with healthy breeder flocks. Goodmanagement practices, focused on the health and performance potential of day-old chicks, includesmonitoring all breeder flocks and hatchery hygiene on a regular basis. Traceability of each batch ofchicks or poults from hatchery to breeder farm helps to detect the source of problems and their elimi-nation.

References

can be obtained from the author.

Zusammenfassung

Bruteierlieferbetriebe und Brüterei in gemeinsamer Verantwortung für die Produktionvon Qualitätsküken

Wirtschaftliche Produktion von Geflügelfleisch und Eiern beginnt mit gesunden und leistungsfähigenEintagsküken. Auf deren Produktion sind Brütereien spezialisiert, die wiederum von der Lieferungvon Bruteiern definierter Qualität aus spezialisierten Bruteierlieferbetrieben abhängen. Die hierarchischeGliederung in der modernen Geflügelproduktion in Zucht-, Vermehrungs- und Produktionsbetriebeerleichtert die systematische Eradikation vertikal übertragbarer Krankheitserreger und den Informations-austausch über die jeweils verfügbaren Möglichkeiten, die horizontale Übertragung von Erregern zuunterbinden.

Die Geflügelindustrie hat aus eigenem Interesse erhebliche Fortschritte in der Kontrolle vonGeflügelkrankheiten erreicht. Gesetzliche Vorgaben der EU sollen dazu beitragen, die Lebensmittel-sicherheit in den Mitgliedsstaaten weiter zu verbessern und insbesondere das Risiko von Salmonellosenund anderen Zoonosen zu begrenzen. Integrationen bzw. feste Verträge zwischen Brütereien undBruteierlieferbetrieben helfen, die Verantwortung zu definieren und konsequent auf vereinbarte Zielehinzuarbeiten.


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Mutilations in poultry in European poultry production systems

Thea Fiks - van Niekerk and Ingrid de JongAnimal Sciences Group, Wageningen University and Research Centre, NL

[email protected]

Introduction

Mutilations of animals, like beak trimming, have been subject of discussion for many years. Opponentspoint out the lack of respect for animal integrity and the stress and pain it causes to the animal.Although supporters argue that omitting mutilations can lead to harmful pecking behaviour causingpain and stress as well, there is a growing societal plea for adapting husbandry systems according tothe behavioural needs of animals instead of mutilate animals to fit them into current husbandrypractices. Better management can contribute to reducing the propensity of feather pecking in layinghens, for example, and increasing knowledge on this issue results in more success for farmers thatkeep non-mutilated poultry. It is often questioned, however, whether intensive poultry productionsystems will ever be able to do without mutilations.

Many studies have been conducted aiming at finding alternatives for mutilations, but the final solutionis still lacking. Some countries have put a ban on specific mutilations. Farmers in these countrieshave found ways to deal with this, but the discussion on the actual improvement of welfare of birdscontinuous in those countries as well as discussions on the applicability of those solutions in othercountries.

Besides finding alternatives for mutilations, research focused on refining the mutilating technologythus minimizing its adverse effects on the animals. Mutilations are performed at younger age or withmore refined equipment or less tissue has been removed, making the mutilation less stressful andless painful for the bird. This discussion is focussing on „how strenuous is the mutilation for theanimal?“ and „what are possible permanent consequences of the mutilation?“.

In the light of these two approaches, i.e. alternatives for mutilations and refinement of methods, themost common mutilations for poultry will be discussed. In this review we address beak treatments,toe clipping, de-spurring and dubbing in laying hens, parent flocks and turkeys. Finally the situationin Europe with regards to legislation and current practices will be presented.

Mutilations

Not all cutting, clipping or trimming parts of the animal’s body is a mutilation. In this paper a mutilationis defined as removing or damaging a part or parts of the body, not being the horny dead body tissueand feathers. A mutilation therefore is directed on living tissue and often involves nervous and circulatorytissue. Although it is very hard to prove, it is very likely to cause acute pain. Not all tissues, however,are equally innervated and thus it is plausible that the impact will vary for the various mutilations.

Cutting a part of the beak is usually referred to as beak trimming. However, as more gentle methodsare developed that are less strenuous for the animal, this should be reflected in the terminology.Therefore in this paper the more gentle measures are called beak treatments. Also, if beak trimmingand beak treatments are discussed in general, they are referred to as beak treatments. Beak trimmingwill only be used for treatments of birds of 5 weeks or older.

Not all mutilations are applied to all species. In table 1 an overview is given of the mutilations thatwill be discussed in this paper and the species that are involved. As this paper addresses only muti-lations applied in the Netherlands, some mutilations common in other countries are not discussed.An example is beak trimming in Ducks, which is not allowed in the Netherlands.


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Table 1 Overview of most common mutilations per species (the indicated mutilations arenot always applied on all genotypes)

1 For broiler breeders this implies removing the nail of the inner toe (to distinguish the various male lines) and cutting the toe membrane(toe slit) or applying a wing band to identify individuals of genetically different groups, for layer breeders this implies the application ofa wing band for identification of individuals on pure line level and toe slits for distinguishing the various genetic Lines.

2 Desnooding of turkeys is not applied in the Netherlands anymore and therefore is not discussed.

Anatomy of the beak

The beak of a chicken is a very specialised organ. It contains many glands and senses, that help theanimal in performing vital tasks, like:

- food seeking, pecking, where the tactile sense of the beak is used to find and select food parti-cles,

- preening, where the beak is used to smooth feathers and to spread feather fat from the tail glandover them,

- nest building behaviour, where the beak is used to collect and arrange the nesting material,

- as weapon for offensive and defensive behaviour.

The centre of the beak consists of bone. The tissue around this bone is well innervated. The outerlayer of the beak consists of horny tissue. This layer is thicker towards the tip of the beak.


SpeciesBeak

treatmentDespurring Dubbing Toe clipping Identification1

Laying hens X

Broiler breeding

Parent stock X X X

(Grand)grandparents X X X X

Broiler breeders X X X

Layer breeding

Parent stock X X X

(Grand)grandparents X X X

Layer breeders X X

Layers for vaccineproduction

X X X X

Turkeys2

Breeder stock X

Meat turkeys X

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In selecting food particles the beak is an important tool. It contains several receptors:

- Thermo receptors: these can detect differences in temperature;

- Mechano receptors: these can detect mechanical differences, thus differences in structure;

- Nociceptors, these detect damage of the beak, like for instance beak treatments.

In both chickens and turkeys the receptors are mainly located in the tip of the beak. Further to thebasis the number of receptors decreases (Gentle et al., 1997).

In the tip of the beak the beak tip organ is located. In geese and ducks this organ can be found inboth the upper and lower beak. In poultry this organ is only found in the lower beak. In the beak tip organmany nerves, blood vessels and sensory receptors are concentrated. The beak tip organ improves thetactile sense of the beak, supporting the bird in selecting food particles.

In the beak nerves often end into a receptor, but they can also have free nerve ends. These canmainly be found in the tip of the upper beak and in the beak tip organ in the lower beak. These freenerve ends have similar morphological characteristics as nociceptors in mammals. Therefore it isassumed that these nerve ends in birds act as nociceptors and will register damage of the beak(Gentle and Breward, 1986).

Consequences of beak treatments

Anatomical consequences of beak treatments

The traditional way of beak trimming consists of removing parts of both upper and lower beak. Thisis done by cutting through living tissue, removing or touching blood vessels, bone, skin and hornytissue. In case of severe beak trimming also salivary glands may be touched.

Directly after the beak treatment the wound covers with scar tissue and blood coagulates. Within a fewdays a thin skin layer is formed over the wound. This is replaced by horny tissue after some time(Gentle et al, 1995). The capacity of the beak to re-grow depends on the type of bird, the age thebeak is treated, the amount of tissue that is removed and the extent of damage the treatment hascaused in adjacent tissue. In turkey poults that were beak treated at 0, 6 and 21 days of age, Gentleet al. (1997) found re-growth of bone, cartilage, blood vessels and nerves. However the treated beaksdid not contain sensory receptors and no afferent nerve vessels (nerves that send information from thebeak to the brain), whereas these were abundantly present in untreated beaks. From these findingsit can be concluded that the tactile senses of treated beaks are affected.

In beaks treated at 5 weeks of age Gentle (1986b) found little regeneration. Along the cutting line hefound excessive scar tissue. This can prevent nerve ends from growing into the beak tip, leading toa fairly insensitive beak tip. Instead he found many neuromas right next to the scar tissue. Neuromasare uncontrolled growing nerve ends. At the point where the nerve has been cut, many nerve branchesare formed. If the main nerve re-grows, these branches and thus neuromas can disappear. In severecases of neuromas this will not happen and the branches will stay permanently (Lunam, 2005).Neuromas are not studied in detail in birds, but in mammals it is known that they can spontaneouslyfire many signals to the brain (Breward and Gentle, 1985 in Hughes and Gentle, 1995). These signalscan be interpreted as pain signals by the central nerve centre.

Behaviour after beak treatments

In behavioural studies Gentle et al. (1990) found indications for chronic pain in laying hens whosebeaks were trimmed at 16 weeks of age. The pullets showed clear changes in behaviour, directedon preventing tactile stimuli on the beak tip (less pecking to objects in the environment, less bill wiping,drinking of hot or cold water). They avoided those behaviours up to 6 weeks after beak trimming,whereas the beaks were healed after 3 weeks. According to Gentle et al. (1990) this indicates possiblechronic pain in the beak. Duncan et al. (1989) also found clear differences in behaviour between


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trimmed (at 16 weeks) and untrimmed hens. Especially preening behaviour and pecking to the envi-ronment was reduced and inactivity increased. Also feed and water use decreased, but this cameback to normal levels quite soon, whereas the earlier mentioned behaviours only reached the orig-inal level 5 weeks after the treatment.

Age of beak trimming

Gentle et al. (1997) did not find any neuromas in beaks of turkeys that were treated at young age (0,6 and 21 days of age) whereas he did find them in beaks of layers trimmed at 5 weeks of age. Hughesand Gentle et al. (1995) concluded that neuromas do not develop in fast growing beaks of very youngbirds. This was confirmed in a study of Gentle et al. (1997), where they treated the beaks of layerchicks at 1 or 10 days of age (1/3 of the beak was removed, measured from the tip to the nostril).None of the chicks developed scar tissue. The beaks had a fast regrowth, but the afferent nervesand sensory receptors were missing. The findings of Lunam and Glatz (1997) do not match this. Theytreated the beaks of layer chicks in the hatchery. The group that was treated moderately (1/2 of beakremoved) had neuromas at 10 weeks of age, but not at 70 weeks of age. In contrast to the findingsof Gentle et al. (1997) these beaks did contain sensory receptors with normal nerve ends, althoughthe number was lower than in untreated beaks. The beaks that were trimmed severely (2/3 of beakremoved) developed a lot of scar tissue and neuromas, that were still present at 70 weeks of age. Inthese beaks no sensory receptors were found.

From the above it can be concluded that early treatment of beaks causes the least problems withscar tissue and neuromas, but will result in more re-growth (Gentle et al. 1997, Lunam and Glatz,1997). Glatz (2000) reviewed beak trimming at various ages and possible consequences. His findingsare in short:

Beak treatment in the hatchery at 0 days of age: Provided the beaks are not cut too short this willresult in beaks without neuromas and a partly regained tactile sense. Body weight of these birds maybe slightly lower, but no consequences for egg weight and egg production are recorded. Some authorsreport a higher mortality in the first week of age. Other authors could not confirm this. If performedprecisely higher mortality is not necessary. Although treatment at this age is not ideal as it falls togetherwith other treatments (vaccinations and moving to rearing house), there are good possibilities tocombine treatments (e.g. robot that combines beak treatment and vaccination). In some occasionsthe pullets are beak treated a second time at a later age because of too much re-growth of the beaks.In large countries with long distances between farms it may not be convenient to perform beaktreatment at the farms and treatment in the hatchery is preferred.

Beak treatment at 5 - 10 days of age: At this age no neuromas are expected provided beak treatmentsare not too severe. The beaks will re-grow partly, but less than in the situation of treatment at 0 daysof age. Effects on body weight of the pullets are not expected. Several authors didn’t find an effecton growth, but found better egg production compared to birds that are treated at a later age. Re-growth is in some (non-European) countries the reason to treat again at 10-14 weeks of age.

Beak trimming at 4 - 8 weeks of age: Little re-growth is expected. Neuromas may occur, but it isunclear if these are permanent or will disappear. Van Rooijen and Van der Haar (1990) found betterbeaks (less abnormalities) when treated at 3 weeks of age compared to treatment at 6 weeks of age.In the rearing period the treatment may lead to temporarily lower feed and water intake and thus ashort stagnation in growth. Before the EU-Directive 1999/74 was adopted beak trimming usually wasperformed at 6 weeks of age, leading to adequate control of feather pecking and cannibalism.

Beak trimming at 8 - 16 weeks of age: The risk for permanent neuromas is higher if birds are beaktreated at an older age. Regrowth hardly occurs, but mortality as a result of the treatment may behigher compared to treatments at younger age. Van de Haar and van Rooijen (1991) found morebeak abnormalities in birds trimmed at a later age.


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How much is removed

Various researches indicate that the extent to which the beak has been trimmed or treated has amajor influence on the final result. Shorter beaks result in better feather quality than longer beaks.Also mortality due to feather pecking and cannibalism is lower when beaks are trimmed shorter. Incontrast, birds with shorter beaks have more problems with their feed intake compared with birdswith longer beaks (Kuo et al, 1990; Andrade and Carson 1975; Craig and Lee, 1990; Gentle, 1986a;Cunningham, 1992; Hughes en Gentle, 1995). This difference is more pronounced when feed isprovided in larger particles, due to more sensitive beaks (Gentle, 1986a; Hughes en Gentle, 1995).

Van Rooijen and Stufken (1991) studied shorter and longer beaks (after trimming) and concludedthat longer beaks are preferable, because:

- the wound on the beak will heal better with a horny layer over it and without scar tissue

- less abnormalities occur in beaks that are cut less severely

- beak treatments are less strenuous, because less tissue is removed.

Lunam (2005) stated that the amount of tissue that is removed has a major influence on the results.She came to the following categories:

- mild treatment: 1/3 of upper and lower beak of layers and turkeys

- moderate treatment: ½ of upper beak and 1/3 of lower beak

- severe treatment: 2/3 of upper beak and ½ of lower beak

When applied at day-old, the mild treatment did not result in any neuromas. The moderate treatmentresulted in neuromas that disappeared at later age. In the severe treatments neuromas were stillpresent at an older age. Schwean-Lardner et al. (2004) removed up to 50% of the beak at 0, 10 and35 days of age without any neuromas as result, which is in accordance with the findings of Lunam(2005) for the moderate treatment.

Lunam and Glatz (1997) concluded that there is a critical amount of beak tissue that can be removed.If more is cut off, the beak will not be able to recover and scar tissue and neuromas will be presentpermanently. In those cases the tactile abilities of the beak will not recover. If less of the beak isremoved, the beak will recover without scar tissue and no permanent neuromas will develop. Alsothe tactile senses will recover to some extent. Beak treatments will always lead to a reduction of tactilesenses of the beak.

Methods of beak treatments

For a beak treatment of laying hens, layer parents, layer type pure lines and broiler breeders a partof both upper and lower beak is removed. This is done during the rearing period. Usually a device isused that cuts part of the beak off with a hot blade that sears up the wound. There are several varietieson this concept. For pullets of 6 weeks of age and older a cross bar is used as beak support. Thebeaks are positioned on the support, and the blade cuts through the beak with the cutting edge strikingthe beak support. This method demands high skills to realise a uniform result. For young chicksusually a gauge plate is used. This is a thin, stainless steel plate with a hole through which the beakis inserted. The blade moves behind the plate thereby cutting the beak. The extent that is cut offdepends on the chosen size of the hole in the gauge plate (that can be varied). Although with thismethod it seems easier to obtain a uniform result, this will also depend on the skills of the worker.Small chicks should not be pushed in as far as larger chicks. The method with the gauge plate isavailable in a normal straight shape and in a V-shape. In the straight version the knife is straight andmoves vertically, in the V-shaped version the knife is V-shaped and moves horizontally. The advantageis said to be the fact that the beaks are shorter in the middle compared to the upper and lower points.This would reduce their ability to pull feathers. Although this may result in difficulties in eating (Andradeand Carson, 1975), a skilful application of this method should not give this problem. Reuvekamp andVan Niekerk (1997) did several tests with straight and V-shaped blades. They let skilful workers use


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either a straight blade or V-shaped blade (both with a gauge plate) to treat 7 day old chicks. Nodifferences were found between the two methods, beak shapes did not differ, no beak abnormalitiesoccurred and production results were good (Van Emous, 1999; Van Emous et. al, 1998, 1999b, 2000;Van Emous and Van Niekerk, 1999c; Reuvekamp and Van Niekerk, 1999a; Van Niekerk, 1998).

For turkeys only the upper beak is treated during the rearing period. Nowadays this is done with ahigh energy infrared source that treats the beak tissue without any bleeding. The infrared sourcedoesn’t cut or burn, but treats the horny outside layer and the underlying basal tissue. Within a weekthe outer layers of the beak turn soft and after two weeks the sharp tip has eroded away. Althoughthe method is not painless, the use of infrared seems to cause less acute and less chronic pain andone can conclude that the method is more welfare friendly to treat beaks than traditional methods.The method is already being used for turkeys. First research results indicate that the method is applic-able also for layers and broiler breeders (Marchante-Forde and Cheng, 2006a, b, c)

Advantages of beak treatments

Beak treated birds perform less effective feather pecking and feather pulling, leading to less damageto the pecked bird. Beak treatments reduce the risk for cannibalism (Van Emous et al., 2001a; EFSA,2005), that clearly reduces suffering of a part of the animals.

Many publications report a better feather cover, lower mortality, lower feed intake and lower feedconversion ratio in flocks that are beak treated (Blokhuis et al., 1987; Craig and Lee, 1990, Hughesand Michie, 1982; Van Rooijen and v.d. Haar, 1990). The better feed conversion ratio can mostly beled back to better feather quality (Blokhuis et al., 1987) and less feed spillage (Hughes and Gentle,1995). The lower mortality and better feed conversion ratio will also lead to economic advantages. Several researchers showed that higher mortality due to the treatment will not occur provided thetreatment is applied skilfully (Andrade and Carson, 1975; Van Rooijen and Van der Haar, 1990; Craigand Lee, 1990, Carey, 1990; Struwe et al., 1992).

Disadvantages of beak treatments

First and foremost any mutilation, including beak treatments, will affect the integrity of the animalinvolved. The animal is being adapted to the environment, whereas from the point of view ofsafeguarding the integrity of animals the environment should be adapted to the animal. From thispoint of view, performing mutilations may be seen as defending the symptoms of inadequate husbandrysystems, rather than solving the problems associated with these systems. Another disadvantage is theacute pain associated with beak treatment itself. Grigor et al. (1995) recorded resistance and vocalisationof chicks that were treated, especially when using a hot blade. Following the period of acute pain aperiod follows in which the animal is probably fairly pain-free (Duncan et al. 1989, Gentle et al. 1991in Hughes and Gentle, 1995). The reason is that the nociceptors (that register pain) are cut off and thenerve endings themselves do not send any extra signals. This pain-free period sometimes can last for26 hours, after which the pain sensation will return, probably as a result of regained ability of thenerve end to send signals. Thereafter a period of chronic pain follows, that depending on the extentof the mutilation may last up to 6 weeks after treatment (Gentle et al. 1990). In case of permanentneuromas there are strong indications that at least part of the animals will experience chronic painduring the rest of their life.

Apart from neuromas, also abnormalities may occur as a consequence of beak treatments, causingpain or distress to the animal. Van Rooijen and Stufken (1990) have described several abnormalities.When the horny layer is not recovering well, the result will be a fairly soft beak tip, which is verysensitive and easily wounded. Other abnormalities are excessive scar tissue, too long lower beaks,odd beaks, too short beaks, etc. Abnormal beaks can hinder hens in their feed intake leading toreduced production.

A severe beak treatment may (temporarily) reduce feed intake so much that growth and developmentof the bird is reduced. This results in lower body weight at the start of the laying period and later onsetof lay.


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Other disadvantages focus on the image of the poultry industry, which finds it difficult to convincewelfare-oriented consumers that beak treatments may be necessary and on balance beneficial ifdone correctly. As a minor disadvantage, the cost of beak treatments should be mentioned, which iseasily recovered by reduced feed intake of better feathered hens.

Other mutilations

Although beak treatment is the most widely applied mutilation, involving various species, there aremore mutilations applied to poultry. Although there are always specific reasons why mutilations areapplied, they do affect the integrity of the animal involved and thus efforts should be undertaken tomake them redundant.

De-spurring

Spurs of broiler breeder cockerels (parent or grandparent males) can cause deep wounds on thethighs of the hens. Therefore spurs are mostly treated directly after hatch. By pushing the spurs brieflyagainst a hot spot, growth of the spurs is stopped. Usually no or almost no mortality is caused by thismeasure. As far as known no research has been conducted to investigate if de-spurring can cause acuteand/or chronic pain. Gentle and Tilston (2000) found many nociceptors and nerves in the skin ofpoultry legs. It is therefore reasonable to expect acute stress and pain caused by de-spurring. It isunknown whether any long-term effects occur, but considering the age and extent of the mutilation itis not likely that permanent neuromas will be formed.

Some breeds don’t have to be de-spurred, as males tend to have short spurs. However, a smallpercentage of these males will develop long spurs later in life, making a treatment of adult malesnecessary. This usually is done with a pair of scissors. Although no research has been done on this,de-spurring of adult cocks will be painful. Whether neuromas will occur in that situation is not known.

Cockerels of egg-type chickens also develop spurs, but they are not de-spurred. Due to their lower bodyweight, they are unlikely to harm the females at mating. Individual hens of some strains can beobserved to develop spurs at later age, which presents a risk of getting caught in poorly designedcage floors, but prophylactic de-spurring of hens is seldom practiced.

Dubbing

Dubbing (cutting of single combs) is widely practiced in day-old parent, grandparent and purelinecockerels of egg-type and meat-type chickens for two main reasons: to identify sexing errors duringrearing and to avoid losses due to excessive comb growth during adult life. If broiler breeders arereared sex-separate, dubbing to detect “sex slips” is not necessary, and intact combs may even beadvantageous for sex- separate feeding. In brown-egg layer parents, dubbing may not be necessary,because the sex is identified by colour and the combs are smaller than in White Leghorns.

Undubbed White Leghorn males would have reduced vision, abnormal feed intake, physical difficultiesto mate and resulting poor fertility. Also these too large combs prevent males from eating, causinghigher mortality. In case parents are kept in cages, e.g. for producing vaccine eggs, dubbing is alsoconsidered necessary to prevent injuries. Dubbing is practiced in the hatchery with small (not heated)scissors. If dubbing is performed correctly there is no bleeding afterwards. To our knowledge, noresearch has been done to investigate possible acute or chronic pain of this measure.

Removing (parts of) the comb may have an effect on communication between birds. As one of thesecondary sexual characteristics the size of the comb may influence the acceptance of the male bythe female and the social status of the male (Johnsen et al., 2001; Parker and Ligon, 2002). Impairedsexual signals may hamper sexual behaviour and reduce successful matings with lower production asa result (Jones and Prescott, 2000). Research however did not find an effect of dubbing on percentagefertile eggs, production and sexual activity of males (Long and Godfrey, 1952; Fairfull et al., 1985).


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A possible disadvantage of dubbing may be a reduced ability for thermal regulation (Khan and Johnson,1970). In hot climate areas with open housing, we therefore often find broiler breeders and brown-egg layer parents with undubbed combs.

Toe clipping

The clipping of toes of broiler breeder cockerels is done to prevent injuries of the hens caused duringmating. At this moment only the hind toe of all cockerels of various meat types is clipped. The sameapplies to meat type grand parents. In several other countries (also in Europe) it is common practiceto also clip the inner toes (forwardly directed) to prevent hens being injured during mating. Alsocockerels used for the production of vaccine eggs are toe clipped (hind toe).

For layer type cockerels that are weighing less, this measure is not necessary and thus not applied.

Like despurring and dubbing toe clipping is carried out directly after hatch with a device with a hotblade or hot wire. Research showed that, like in beak trimming, toe clipping may cause neuromas,although these are smaller and the effects seem to be less severe than in beaks (Gentle and Hunter,1988). Nevertheless the procedure itself is stressful and causes pain and there is a risk for neuromaformation and thus for chronic pain.

Patterson et al. (2001) did use a microwave device to remove toe nails of chicks. Within 24 hours thebasis of the treated toe nails turned white and the nail fell off in 3 days. Although the method worked,negative results were recorded for growth and the goal (less body scratches) was not reached. Noother alternative methods are known.

Identification

Mutilations to identify birds are applied to distinguish pure lines, prevent sex failures and to identify indi-vidual birds in breeding programs. If other mutilations are already applied, these often are also usedfor identification. If no other mutilations are applied, various measures are possible to secure identi-fication of single birds. For broiler breeders this implies removing the nail of the inner toe (to distinguishthe various male lines) and cutting the toe membrane or applying a wing band to identify individualsof genetically different groups; for layer breeders this implies the application of a wing band for iden-tification of individuals on pure line level and cutting the toe membrane for distinguishing the variousgenetic Lines. Removing the nail of the inner toe can be regarded in the same way as toe clipping. Inboth applying a wing band and cutting the toe membrane the mutilation is directed to not much morethan skin tissue. Although no information on these measures is available it is not likely that theycause significant pain.

Situation for various poultry species

Laying hens

In certain situations (or under certain conditions) it is possible to omit beak treatments in laying hens.In cages with small groups (up to about 10 birds) the risk for outbreaks of pecking and cannibalism isnot very high. By reducing the light level pecking can be restricted and hens with intact beaks canbe kept.

In cages the risk for pecking increases with group size (Fiks et al., 2003;Tauson et al., 2005). Measuresto reduce pecking, like provision of distraction materials, do not completely prevent the developmentof feather pecking but only reduce the risk to some extent. Although recent findings indicate thatmortality can be low in flocks with intact beaks in large group cages, this requires high managementskills and optimization of all factors contributing to the risk for cannibalism (EFSA, 2005; Blokhuis etal., 2007).

In non-cage systems there are more possibilities to prevent feather pecking and cannibalism. Thesemeasures however do cost labour and money and are often not easy to apply on larger farms with


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more houses and large flocks. The group sizes of these large flocks also mean a higher risk comparedto small non-cage flocks. Finally in non-organic farming stocking densities are probably higher thanrequired for successful keeping of non-treated hens. Applying state-of-the-art husbandry, it does notseem advisable to house large groups of laying hens without beak treatments (EFSA, 2005).

To prevent problems with pecking various management measures are advised. None of these measurescan exclude damage by pecking behaviour, but research on more promising methods continues andis certainly important. In a pilot study with laying hens it was shown that sandpaper on the bottom ofthe feed trough blunted the beak tip. The group with sandpaper had a lower mortality than the control,but feather cover did not differ (Fiks and Elson, 2005).

Fundamental research should address a better understanding of the causes of feather pecking andcannibalism. Areas of interest are behaviour, genetics, nutrition, neurobiology and physiology.

Breeder flocks

Not de-spurring broiler breeder cockerels may be possible in lines with relatively small spurs. Cuttingof the hind toes and beak treatments in broiler breeders seem to be necessary measures for the nearfuture. Cockerels with intact beaks and non-clipped toes cause high mortality and a lot of injuredhens, and up to now no solutions for these problems have been found (Van der Haar et al., 2002).Dubbing and cutting of the inner toes is not performed anymore in broiler breeders in various countries.

For broiler breeders aggressive mating behaviour seems to be an important cause of injured hens(Jones and Prescott, 2000). Research to the cause of this behaviour may lead to possibilities toreduce or omit mutilations of broiler breeders.

Dubbing of cockerels of layer parents may not be necessary in brown-egg lines, because they havesmaller combs and sex failures can be recognized. For White Leghorns, grandparents and purelines,this measure is still considered as necessary. Toe clipping and de-spurring is not performed on layertype of birds. At the moment there are insufficient alternatives to omit beak treatments (see layers). For parents used for vaccine production, de-spurring and toe clipping may not be necessary, butdubbing is.

Turkeys

Mutilations applied in turkeys are beak treatments and desnooding. The latter is more and moreomitted. Beak treatments used to be done with a laser burning a small hole in the upper beak at thehatchery. The beak tip then would fall off in about 5 days. Nowadays mostly the microwave methodis used in the hatchery, resulting in erosion of the beak tip within a few days.

From extensive research in the Netherlands and other countries in meat type turkey production, no satis-factory solution has been found to reduce pecking in untreated turkeys to an acceptable level (Fiks etal., 2006, Frackenpohl, 2004; Veldkamp, 1998). All forms of enrichment of the environment only havea short-term effect on the behaviour of turkeys. To keep the enrichments attractive, materials shouldbe modified frequently. Reducing light intentensity to very low levels has an effect, but from the pointof view of natural explorative behaviour it is a less desired measure. On commercial farms at thismoment pilot studies are running where turkeys are offered a covered veranda. In the veranda itselfand through the outlet openings the turkeys are exposed to large amounts of light, so dimming oflights is not an option.

The current situation in Europe

There is a lot of variation between European countries with regards to legislation and practice ofmutilations in poultry. Only beak treatments of laying hens are regulated on a European level. InCouncil Directive 1999/74/EC of 19 July 1999 laying down minimum standards for the protection oflaying hens, beak trimming is regulated in the annex, which states under no. 8: „ Without prejudice


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to the provisions of point 19 of the Annex to Directive 98/58/EC, all mutilation shall be prohibited. Inorder to prevent feather pecking and cannibalism, however, the Member States may authorise beaktrimming provided it is carried out by qualified staff on chickens that are less than 10 days old andintended for laying.“ For the other mutilations no European legislation is available and countries differin regulations and in practice.

The strictest legislation regarding mutilations is in force in Scandinavian countries (Norway, Sweden,Finland), where beak treatments are not allowed and other mutilations are also banned or strictlyregulated (Table 2). In Denmark, Germany and Belgium beak treatments are only allowed if there isproof or a strong indication that in the given situation omitting beak treatments will cause seriouswelfare problems. In practice this means that on almost all farms, and certainly in non-cage systems,beak treatments are applied. In the UK, the Netherlands and Austria beak treatments are still allowed,but National legislation is in force to regulate the application of mutilations. In the UK and the Netherlandsa date for banning beak treatments is already set, although new insights may lead to modification ofthe (proposed) legislation. In Austria over 95 % of the hens are not beak trimmed.

With regards to other mutilations, many countries don’t have any regulations. In general countrieswith strict National legislation regarding beak treatments also have regulated other mutilations. MostSouthern and Eastern European countries have no other legislation regarding mutilations except theCouncil Directive 1999/74.

The actual situation in European countries is not much different from what their legislation prescribes.In some situations exemptions on a ban on beak trimming are made routinely, but in other countriesbeak treatments are not performed anymore, whereas there still are legal possibilities.

Table 2: Legislation regarding mutilations in Europe

No information: Bosnia, Croatia, Romania, Serbia-Montenegro, Slovenia, Slowakia

Summary

In commercially kept poultry, mutilations are applied to prevent behaviour of individuals which maybecome harmful for group members. Mutilations discussed in this paper are: beak trimming (in layinghens, breeders of egg-type and meat-type chickens and turkeys), de-spurring (in meat-type parentmales), toe clipping (in broiler parent and grandparent males), dubbing (in egg-type and meat-typeparent males) and various ways for individual identification (of egg-type and meat-type parents andgrand parents).

Mutilations cause acute pain when applied and can in some situations cause chronic pain sensation,depending on the age and extent of the mutilation. Although mutilations are mostly done to preventinjuries to birds, opponents feel there should be alternative management strategies to safeguard the


BEAK TRIMMING OTHER MUTILATIONS

Allowed (EU-Directive)

Strictlyregulated

Not allowed Not regulated,allowed

Regulated, but (mostly)allowed

Regulated and (mostly) not allowed

Czech Rep.FranceHungaryIrelandItalyPolandSpain

AustriaBelgiumDenmarkGermanyNetherlandsSwitzerlandUK

FinlandNorwaySweden

Czech Rep.FranceIrelandItalyPolandSpain

AustriaBelgiumDenmarkFinlandHungaryNetherlandsSwitzerlandUK

NorwaySweden

Vol. 42 (1), April 2007, Page 45

animals from injurious behaviour. However, for the current intensive as well as organic poultry husbandrysystems these alternatives do not provide a satisfactory control of injuries and mortality.

A European Directive is in force only for beak trimming of laying hens. Local governments may alreadyhave or plan to impose more strict regulations and in some countries even ban mutilations. In generalthe situation in practice is in accordance with the legislation.

Zusammenfassung

Eingriffe beim Geflügel in europäischen Haltungssystemen

Eingriffe beim Geflügel werden vor allem praktiziert, um einem Verhalten von Tieren vorzubeugen,das sich nachteilig für die Tiere selbst und andere Tiere im Bestand auswirken kann. Im Einzelnenwerden in dieser Übersicht folgende Eingriffe behandelt: Schnabelstutzen (bei Legehennen, Elterntierenund Puten), Sporenbrennen und Zehenschneiden (bei Broilerelterntierhähnen), Kämmeschneiden(bei Lege- und Mastelterntieren) und verschiedene Arten individueller Kennzeichnung.

Eingriffe können bei ihrer Anwendung akute Schmerzen und je nach Alter der Küken und Intensität derEingriffe chronische Schmerzen verursachen. Obwohl die Eingriffe vor allem Leiden anderer Tieredurch Pickverletzungen verhindern sollen, fordern Gegner dieser Praktiken andere Lösungen. Nachheutigem Wissensstand lässt sich jedoch eine befriedigende Vorbeuge gegen Kannibalismus undFederpicken ohne Schnabelbehandlung nicht erreichen.

Eine Europäische Direktive zu Eingriffen gibt es bisher nur für das Schnabelstutzen von Legehennen.Einzelne Mitgliedsstaaten der EU können schärfere Regeln gegen Eingriffe erlassen und haben diesz.T. bereits getan. Die Praxis folgt im Allgemeinen den gesetzlichen Vorgaben.

Acknowledgement

This study has been financed by the Dutch National Egg Board. The authors also would like to thankWPSA Working Group 9 (Poultry Welfare and Management) for providing information from variousEuropean countries.

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